Regulators fined Wells Fargo $185 million last week for a scheme in which employees created up to 2 million accounts that customers did not authorize. (Karen Bleier/AFP/Getty Images)

Federal prosecutors have launched an inquiry into aggressive sales tactics at Wells Fargo after revelations that thousands of its employees secretly created accounts customers didn’t ask for to meet sales goals, according to people familiar with the matter.

The investigation, which is being conducted by the U.S. attorney’s office in New York, is preliminary and may not produce charges, said one person familiar with the matter. That person said that the banking giant had been served with subpoenas, but that the prosecutors have not decided whether the case warrants criminal or civil charges.

The investigation escalate an already embarrassing episode for San Francisco-based Wells Fargo.

Regulators fined the bank $185 million last week for a scheme in which employees created up to 2 million accounts, for services such as credit cards and savings accounts, that customers did not authorize. In some cases, the employees took money from an established account to create a new one. Some customers were then hit with assorted fees for accounts they didn’t know they had, the regulators charged.

The activity peaked in 2013 and mostly occurred in the Southwest part of the country, company officials have said.

Wells Fargo CEO John Stumpf speaks at the Bay Area Council Outlook Conference on May 17, 2016 in San Francisco. (Justin Sullivan/Getty Images)

“How probable is it that you would have a firm-wide, multiyear scheme involving thousands and thousands of people that senior leaders weren’t aware of?” said Jordan Thomas, a partner at Labaton Sucharow and a former Justice Department trial lawyer.

“I think the smart money is that some senior leaders were aware, and it is for that reason that prosecutors are apparently making an inquiry,” he said.

Wells Fargo has apologized to customers and said it would end the aggressive sales goals critics say pushed employees to break the rules. The company said last week it had dismissed 5,300 employees over five years for creating the unauthorized accounts, including some managers.

“On average 1 percent [of employees] have not done the right thing, and we terminated them. I don’t want them here if they don’t represent the culture of the company,” John Stumpf, the company’s longtime chief executive, said in an interview Tuesday with The Washington Post.

Stumpf is expected to testify before the Senate Banking Committee next week on the affair.

The Consumer Financial Protection Bureau fined Wells Fargo $185 million in penalties for allegedly creating 2 million bank and credit card accounts for customers without their knowledge. (Reuters)

Wells Fargo has long cultivated a reputation for staying out of the regulatory headaches that have dogged some of its biggest competitors. That reputation is now at risk as lawmakers, regulators and even Wall Street analysts question how one of the country’s largest banks could have allowed such behavior to fester for years.

The federal investigation also comes a year after the Justice Department said it would more aggressively pursue cases against individual company executives, not just corporations. For years, prosecutors endured criticism for not doing enough to prosecute high-level executives for financial misconduct, particularly in the wake of the 2008 financial crisis.

The Wells Fargo case, legal experts say, is an opportunity for federal officials to reflect that new focus.

Wells Fargo declined to comment, and a spokesman for the U.S. attorney for the Southern District of New York could not be reached for comment. The Wall Street Journal, which earlier reported the existence of an investigation, said the U.S. attorney for the Northern District of California, where Wells Fargo is based, is also investigating the matter. A spokesman for that office declined to comment.

To build a case against a company executive, prosecutors would have to show “they knew there was a plan to create false accounts to drive up sales,” said Brandon L. Garrett, a professor at the University of Virginia School of Law.

Even if it appears that the executive purposefully attempted to avoid knowing about the fraud, prosecutors may be able to build a case, Garrett said. “They don’t have to participate if there is willful negligence,” he said.

Wells Fargo has been the country’s largest bank by market value for years, but lost that perch to JPMorgan Chase this week as its stock price plummeted. It has fallen about 8 percent since regulators announced the $185 million fine.