The lawyer retained by the city, Patrick J. Egan, is the co-chair of Fox Rothchild’s white-collar criminal defense practice. He recently represented New York “taxi king” Evgeny Friedman in a multi-million fee theft case.

Egan confirmed in a statement issued Thursday that the probe is federal.

“We have been retained by the city to represent Councilman Johnson in connection with an investigation being conducted by the United States Attorney’s Office for the Eastern District of Pennsylvania,” Egan said.

“We have reviewed the evidence related to that investigation and are confident that the Councilman has done nothing improper, much less illegal,” Egan said. “We are confident that when all information related to the investigation comes to light the Councilman will be vindicated.”

Johnson declined to comment when asked about the arrangement at City Hall on Thursday.

“I don’t really have any comment on it, currently at this moment. So that’s all I have at this current time,” the Point Breeze councilmember told PlanPhilly.

Former federal prosecutor William A. DeStefano said that the city’s charter requires it to cover legal fees for public officials under investigation up until the time they are indicted on criminal charges.

“It’s to assist the person under investigation. To handle grand jury subpoenas or FBI officials who want to interview or take a statement from the councilman,” he said.

None of Johnson’s staffers are being represented by attorneys paid for by the city, according to the Law Department.

An Inquirer investigation last year reported that FBI agents had subpoenaed records related to a land sale approved by Johnson. In the past, indicted Councilmember Bobby Henon had requested similar services in connection with a federal corruption investigation –– although he used these services sparingly.

DeStefano said the policy was aimed at protecting public officials.

“It’s rooted in the presumption of innocence. Unless someone is found guilty, there is a constitutional presumption he’s innocent,” DeStefano said. “The investigation could end with no criminal charges. Many do. Although this one may not turn out that way.”

Johnson’s chief of staff did not offer additional comments. A spokesperson for Johnson did not immediately respond to calls and emails for comment.

The Inquirer reported that sources said the investigation may be linked to an earlier bribery inquest involving Universal Companies, a charter school operator founded by record producer Kenny Gamble. Court records show that one of the defendants in that case, Michael Bonds, agreed to plead guilty in May. However, he has not yet been sentenced and plea documents in the case remain under seal.

DeStefano said that was likely an indicator the case was linked to a larger investigation and that Bonds had agreed aid federal investigators.

“In general, that means someone has agreed to cooperate with the government and plead guilty. And that an investigation is still ongoing against other people,” DeStefano said. “It’s usually sealed because they don’t want to alert the other subjects of the investigation…And this fellows cooperation could potentially include testifying against other people if and when they’re indicted.”

Attorneys for Bonds did not return calls for comment.

This is an evolving story that will be updated. PlanPhilly reporter Jake Blumgart contributed reporting to this article.