At 5:25 p.m. Tuesday, Zuhair Maliky's flip-top mobile phone chimed to life. A relative was calling to say that Ahmed Chalabi was on television, hurling more barbs at Maliky.

"He's calling me an amateur who's trying to play an important role," Maliky said with a laugh as Chalabi's comments were relayed to him.

Maliky is the chief investigating judge at the Central Criminal Court of Iraq. On Saturday, he issued an arrest warrant for Chalabi, a prominent Iraqi politician who used to have close ties to the Pentagon. Maliky is investigating whether Chalabi and members of his party, the Iraqi National Congress, were involved in counterfeiting Iraqi currency. Chalabi, who is in neighboring Iran, has denied the charges and belittled the judge as an incompetent acting at the behest of the U.S. government.

The case against Chalabi, should he return to Iraq, is shaping up to be a key test of the country's new judiciary. To Chalabi and his surrogates, the arrest warrant is incontrovertible evidence that the court system suffers from the same political manipulation it did under the government of Saddam Hussein. To Maliky, the ability to investigate a powerful man such as Chalabi reflects the new independence of Iraq's judiciary.

Chalabi is a former banker with deep enough pockets to hire political strategists and press advisers. Maliky, who has been a judge for less than a year and lives in the same house in which he grew up, has just one assistant -- a clerk who packs a 9mm handgun.

But after flipping his phone shut, the judge insisted he was unbowed by the challenge of taking on one of Iraq's most politically savvy men. "My advice to him is to find himself good lawyers," Maliky said.

Maliky also has issued an arrest warrant for Chalabi's nephew, Salem Chalabi, in connection with an investigation into the murder of a top Finance Ministry official who was looking into whether the Chalabis were illegally occupying Iraqi government property. Salem Chalabi, an American-educated lawyer, is the administrator of the special tribunal set up to try Hussein and his top deputies for crimes against humanity and other offenses. He is currently in Britain.

Maliky said Ahmed Chalabi became a subject of investigation after Iraqi police officers found a substantial amount of counterfeit Iraqi currency during a search of his house in May. The judge, who had been investigating several of Chalabi's aides for other alleged crimes, issued the warrant that led to the search.

Chalabi has acknowledged possessing counterfeit currency, but has said the notes were samples used for a meeting with Iraq's Central Bank in his capacity as chairman of the finance committee of the now-disbanded Governing Council. He has said that the value of the counterfeit currency in his house was 3,000 dinars, or about $2.

Interviewed in his wood-paneled office at the high-security Central Court building, Maliky said Chalabi had much more than $2 worth of counterfeit money in his possession. "I can assure you that the amount that was seized is much higher than what was publicly mentioned," he said.

Chalabi contends that Maliky, who became a judge while Iraq was under U.S. occupation, is being manipulated by Americans. Chalabi's relationship with the U.S. government, which was once so close that his party received a $340,000 monthly stipend, has frayed after disputes over the quality of prewar intelligence supplied by the party, Chalabi's denunciations of the U.S. occupation and his close ties with Iran. Shut out of Iraq's U.N.-selected interim government, Chalabi has been trying to curry favor with Iraq's Shiite Muslim majority by casting himself as a proponent of close ties with Shiite-dominated Iran and an opponent of the interim administration.

"The principal motive is to keep me out of the political process or hamper my participation in it," Chalabi told the Reuters news agency in Tehran, the Iranian capital, on Tuesday.

Chalabi's aides contend that Iraq's interim prime minister, Ayad Allawi, is conspiring with the U.S. government to marginalize the Iraqi National Congress. Allawi had long been a rival to Chalabi; his party was supported in exile by the CIA while Chalabi was backed by the Pentagon. On Tuesday, U.S. troops delivered a written order from Allawi's office to the INC requiring it to vacate its headquarters in Baghdad's posh Mansour district. The building had housed Hussein's intelligence service.

Although various political parties have claimed dozens of government buildings around the country, most of which belonged to intelligence services run by Hussein's relatives, the interim government has focused on trying to evict the INC. An INC spokesman said the party had signed a lease with the U.S. occupation authority for the building in Mansour.

In an effort to take the legal offensive, Chalabi's American attorney said he intended to file suit this week in the United States against the government of Jordan over its seizure in 1989 of a bank that Chalabi had run. "Dr. Chalabi has authorized the filing of a legal proceeding in Washington, D.C., by which he will seek vindication against those in Jordan who have been systematically trying to ruin his business, his good name and his growing influence in Iraq," the lawyer, John J.E. Markham II, said in a telephone interview.

Markham would not provide details about the suit. But the first turn in Chalabi's fortunes occurred in Jordan, where he was charged with embezzlement and fraud in connection with the collapse of Petra Bank, one of Jordan's largest financial institutions. After it was seized, Chalabi was convicted in absentia and sentenced to 22 years of hard labor and a multimillion-dollar fine. Chalabi says the charges were trumped up to discredit him.

In his dim office in Baghdad's Central Court, where the electricity keeps cutting out, Maliky scoffed at Chalabi's claim that he is being ordered around by the U.S. government. "I don't receive orders from anybody," he said. "The moment I receive orders from somebody, I will resign. The judge should obey justice, the law and God."

The judge said he so feared U.S. interference after issuing the warrant to search Chalabi's house that he wrote out a resignation letter that he intended to submit if his order were quashed. "If I was told to back down, I would not be a real judge," he said. "What's the point of not being a real judge?"

Maliky, 38, has degrees in English literature, economics and law. Before the U.S. invasion last year, he had been a practicing lawyer. Then he served as a legal adviser to the occupation authority before a council of judges selected him to be the chief investigating judge for the new Central Criminal Court.

Although he has ordered Chalabi's arrest, the judge said, that does not mean Chalabi would be confined to jail during the investigation. "He could be released on bail," Maliky said. "He's welcome to come to the court and prove he is innocent. If that's the case, he will be released."

Maliky disputed that he was a carrying out a political vendetta against the INC. He insisted repeatedly that he is treating Chalabi as he would treat any other Iraqi.

"I'm just an ordinary judge whose aim is only to make sure nobody is above the law," he said. "We suffered under 35 years of injustice, tyranny and dictatorship. It's time for all this to stop. When I read a case, I forget about the position or the role of the person. I'm just concentrating on the facts and the law."

Staff writer Robin Wright in Washington contributed to this report.

Former Iraqi Governing Council member Ahmed Chalabi, subject of a warrant in a counterfeiting probe, says the investigating judge is acting at U.S. government behest.