LONDON — Until quite recently, Zamira Hajiyeva was living the high life, according to British authorities. She had a $15 million townhouse in London’s tony Knightsbridge neighborhood, a golf club in the English countryside and a gold-plated shopping habit at Harrods.

That was before a British court this year asked the 55-year-old from Azerbaijan an impertinent question: How did she afford those purchases?

That query is at the heart of a bold British push to try to reverse what the government believes is a flood of foreign investment stemming from overseas corruption and criminality.

For more than a decade, ultrarich people from the former Soviet Union, China and the Middle East have turned to London mansions, New York high-rises, and chic properties in Vancouver, Miami and Paris to store their cash. The phenomenon has turned the real estate markets of North American and European cities into the savings accounts of wealthy foreigners — some of whom face allegations of corruption or crime back home.

Regulators on both sides of the Atlantic have failed to stem the tide, which has helped drive property prices beyond the reach of some local residents and, critics argue, facilitated illicit conduct overseas.

Now a new investigative tool being launched by British authorities could serve as a powerful deterrent. But it is fraught, forcing wealthy individuals to demonstrate that they bought property with lawfully earned funds — a departure from legal precedent that required the state to prove the use of illicit money.

“It is quite a dramatic move to put a burden on somebody to explain the legitimacy of their income, versus the reverse burden, which would normally be on the state to show income or property had been unlawfully obtained. We have issues about that,” said Jonathan Fisher, a lawyer specializing in white-collar crime cases.

The case involving Hajiyeva — whose husband is serving a prison sentence in Azerbaijan for embezzlement — is the first of what the government says will be several efforts to deploy the new “unexplained wealth orders” in the coming months.

Under new legislation, law enforcement agencies can seek the orders from a court when they have “reasonable grounds to suspect” that a person lacks enough legal income to explain a large purchase — and has ties to a foreign public official or possible links to crime. If recipients of the orders can’t show that they used legitimate income, the court may allow the government to seize the property.

British Prime Minister Theresa May spoke on May 21 about her government’s efforts to address international money laundering. (Reuters)

Donald Toon, head of economic and cybercrime at the National Crime Agency, which requested the court orders against Hajiyeva, said the government is enforcing the law that Parliament passed. Britain needed an easier way to target suspected dirty money arriving from overseas, he said, because it’s often hard to acquire firm evidence of criminality in foreign countries with unreliable legal systems.

“It cannot be right that, in our view, people are able to acquire and retain property and hold assets in the U.K. where we have a reason for belief that that represents the proceeds of criminal behavior,” Toon said in an interview at the agency’s South London headquarters. The National Crime Agency plans to ask the High Court for “a handful” of additional orders in the next few months, he said. “The aim is to make it easier to remove dirty money from the system.”

That’s a goal other Western countries are pursuing, with mixed results. The United States, for one, is strong at investigating and prosecuting money laundering, but it has “serious gaps” in regulation of the lawyers, accountants and real estate agents who help clients launder money, knowingly or unknowingly, according to David Lewis, executive secretary of the Financial Action Task Force, an intergovernmental body that combats illicit finance.

The United Nations has estimated that criminal funds equal to about 2.7 percent of global gross domestic product may be laundered through the financial system annually.

Unexplained wealth orders are a relatively new tool for attacking the problem, though they have been used in a handful of countries, including Australia. In Britain, judges will issue them only if authorities can show that the recipient has suspected ties to crime or to a public official in a non-European country — a position that could enable them to benefit from corruption without sufficient legal scrutiny, lawyers say.

Hajiyeva is married to Jahangir Hajiyev, who in 2016 was convicted of embezzling money from a state-controlled bank in Azerbaijan. London’s High Court issued an unexplained wealth order to Hajiyeva in February, asking her to explain the purchase of the London townhouse. A second order involved the golf club.

Hajiyeva argued in court that it was her husband’s responsibility to purchase the property, and that she had no knowledge about the payments or the source of the money, court records show. The High Court rejected her attempt to have the first order quashed, saying it was issued on solid grounds.

Hajiyeva has not been charged with a crime in Britain — the unexplained wealth order is a civil investigative tool.

Her home country of Azerbaijan, however, charged her with embezzlement in 2016, saying she worked with her husband to defraud the bank. According to her lawyers, Hajiyeva believes “that the proceedings against her husband were abusive and politically motivated” and that Azerbaijan’s charges against her “are similarly tainted.”

In late October, acting on an extradition request from Azerbaijan, Britain arrested Hajiyeva and jailed her for nine days before releasing her on bail while the courts consider the extradition request.

In mid-November, reporting to a London police station in a chauffeured SUV for her daily check-in — a condition of her bail, along with wearing an electronic tracking device and abiding by a curfew — Hajiyeva declined to comment to The Washington Post on her legal troubles.

London’s rich culture and nightlife and posh boarding schools have made it a magnet for overseas capital, bringing a flood of wealthy foreigners seeking a comfortable life away from their sometimes turbulent home countries.

Foreign money particularly streamed to London after the fall of the Soviet Union in 1991, when privatization of state-owned industries, often through corrupt auctions, created a new generation of millionaires and billionaires. Buyers from former Soviet republics helped drive London housing prices to record highs, causing consternation among Britons who were priced out of the market.

Far from all foreign investment stems from corruption or crime, but in 2015 the National Crime Agency said overseas criminals were laundering billions of pounds through property purchases. Then-Prime Minister David Cameron said British properties were “being bought by people overseas through anonymous shell companies, some with plundered or laundered cash.”

Concerns grew so acute that a pair of anti-corruption campaigners started a “kleptocracy tour” of London, escorting journalists and politicians around wealthy neighborhoods dotted with foreign-owned mansions. The partners are former finance industry executives based in London — Arthur Doohan and Roman Borisovich — who say they fund the effort largely with their own money.

Strolling down a Knightsbridge street in the autumn sunshine last month, Doohan pointed toward a large brick home. “This is Mr. Firtash’s iceberg,” he said, referring to the Ukrainian oligarch Dmytro Firtash, who is living in Austria fighting a U.S. extradition request on bribery charges that he denies. Iceberg, Mr. Doohan explained, means “a house that goes down as far as it goes up” — in this case with an underground swimming pool, he said.

A few blocks away Doohan arrived at Hajiyeva’s townhouse, where all the curtains were drawn. Now that the property is subject to an unexplained wealth order, it “will become a highlight” of the tour, he said. Money laundering “just damages people,” he said. “It damages people in Russia and Nigeria, the places where the money was stolen from. They don’t get roads, schools, hospitals . . . and it damages people in the U.K.,” he added. “The price of property has been driven against the interests of the law-abiding, taxpaying citizens.”

In 2009, a company incorporated in the British Virgin Islands paid $15 million for the townhouse, which is a short walk from the high-end Harrods department store, according to court papers in the Hajiyeva case. In 2015, when Hajiyeva applied for permanent British residency, she told British authorities that she was the beneficial owner of the company, court records show.

The National Crime Agency “contends that there are reasonable grounds for suspecting that Mrs. Hajiyeva’s lawfully obtained income would have been insufficient to obtain the property,” court records show. At the time of the purchase, her husband was chairman of the state-controlled International Bank of Azerbaijan and appeared to be her only source of income, the agency said. His net income ranged between $29,062 and $70,648 a year, according to bank documents submitted to the court.

Hajiyeva’s lawyers say she began visiting London in 2005 and moved there permanently in 2010, after a tumultuous life in her home country. In 2005 she was kidnapped in Azerbaijan by an armed group believed to have connections to the country’s Interior Ministry, according to her lawyers.

“She was treated very badly during her kidnapping, and became very unwell, and she and her husband resolved that they would thereafter endeavor to bring up their family at least in part abroad,” her lawyers said in a court document.

Hajiyeva lived at the house near Harrods and started spending large sums at the department store, which issued her three customer loyalty cards, according to the National Crime Agency. Between 2006 and 2016, a total of 16.3 million pounds ($20.5 million) was spent using those cards, the agency said.

Many of those purchases were charged to 35 credit cards issued by the Azerbaijani state-controlled bank that Hajiyeva’s husband was helping run, according to court records.

Jahangir Hajiyev, meanwhile, was traveling in elite banking circles, attending the annual World Economic Forum meeting in Davos, Switzerland, and helping found a WEF club for up-and-coming companies. The club, he said in a 2007 statement, would “raise the bar for corporate governance and social responsibility for emerging and developed markets alike.”

The National Crime Agency said that in 2013, an offshore trust linked to Hajiyeva spent roughly $13 million on the Mill Ride Golf & Country Club, which is set on 170 acres of rolling countryside in the affluent county of Berkshire. Hajiyeva’s three children attended schools in Britain, including a boarding school in north London, according to her lawyers. One son is studying at a U.S. university.

Much of Hajiyeva’s spending came to a halt after her husband’s December 2015 arrest in Azerbaijan on embezzlement charges related to the bank, her lawyers said.

“The family’s finances and assets in Azerbaijan were effectively frozen. Her bank accounts in the U.K. were closed in 2016, as, of course, were all the credit and loyalty cards,” her lawyers wrote in a court document. “After this date she started to sell personal items and to rely upon the support of friends and family to meet her expenditure, including general household expenditure and school and university fees.”

After a trial in Azerbaijan, Hajiyev was convicted in October 2016 and sentenced to 15 years in prison. He was also ordered to pay his former bank $39 million, British court documents show.

Azerbaijani authorities also came after Hajiyeva, charging her with embezzlement and requesting her extradition from Britain in early 2017. For more than a year and a half, Britain took no apparent steps to extradite her, Hajiyeva’s lawyers say.

In 2017, amid rising anger over housing prices and worsening relations with Russia, Parliament passed legislation introducing the unexplained wealth orders.

The initial court proceedings against Hajiyeva kept her identity anonymous, but after her appeal against the first order failed in October, the court released her name, sparking bold headlines in the British press about her Harrods shopping sprees. One tabloid photographed her walking her tiny dog while wearing what appeared to be Gucci sneakers and carrying an Hermes handbag.

Soon after, Toon said, the National Crime Agency received a tip that Hajiyeva’s daughter was having jewels valued at Christie’s, the auction house. Investigators swooped into Christie’s and seized 49 items worth half a million dollars, including a Boucheron sapphire-and-ruby necklace and a diamond Cartier pendant in the shape of a panther.

The National Crime Agency said that Hajiyev, the jailed banker, had originally purchased some of the jewels and that the “source of the funds” used required further investigation.