SAN FRANCISCO -- Former San Francisco Supervisor Ed Jew asked a federal judge on Tuesday to hold an evidentiary hearing on possible government misconduct related to an alleged conflict of interest by his former defense attorney.

Jew, 47, who resigned from his supervisor post last month, is accused in federal court in San Francisco of trying to extort $84,000 from local business owners in exchange for help in obtaining city permits.

His current lawyer, Stuart Hanlon, filed a motion asking U.S. District Judge Susan Illston to consider at a March 21 court session whether to schedule a future evidentiary hearing.

Hanlon wrote that Jew is not alleging actual misconduct by prosecutors at the moment, but said "the known facts raise serious issues and suspicion." He said an evidentiary hearing is needed to determine whether there is a basis for a defense motion for dismissal of the charges.

Hanlon claimed Jew's former lawyer, Steven Gruel, had a conflict of interest. He said Gruel told the FBI last May 2 about the alleged shakedown, allegedly at the behest of state Sen. Leland Yee, described by Hanlon as "a known political opponent" of Jew. Gruel, now a private defense attorney, had contacts within the FBI because he was formerly a federal prosecutor.

Eighteen days later - after an FBI search allegedly turned up $10,000 in marked bills at Jew's house in Burlingame - Gruel became Jew's defense attorney.

Hanlon contended in the motion that a conflict waiver signed by Jew didn't explain Yee's role, and that prosecutors may have engaged in misconduct by failing to investigate the conflict adequately or tell the judge about it.

U.S. attorney's office spokesman Joshua Eaton said prosecutors would have no comment Tuesday. He said prosecutors would respond later in a written answer that is due by March 11.

Gruel said he couldn't comment on the case because of attorney-client confidentiality. But Gruel's attorney, Richard Zitrin, a legal ethics professor, said the pleading "is nonsense."

"Steven Gruel did not have a conflict of interest and did absolutely nothing wrong," Zitrin said. "He disclosed what he had to disclose."

"Mr. Hanlon must be really concerned about the evidence to blow such transparent smoke as this," Zitrin said.

Adam Keigwin, a spokesman for Yee, said the senator couldn't comment beyond a Jan. 14 statement in which Yee said he was told about the alleged extortion last April and "it was my ethical responsibility to inform the proper law enforcement officials to investigate."

Hanlon said in the filing that Yee was allegedly told of the shakedown accusation by Jaynry Mak, who unsuccessfully ran against Jew for the Sunset District supervisor seat in 2006.

The attorney contended that an evidentiary hearing may show that prosecutors' failure to investigate the conflict "allowed for a criminal investigation of Mr. Jew to take place that was tainted by Leland Yee and Jaynry Mak."

"It is not only concerning, but baffling, that the accusations that began this entire investigation came from Mr. Jew's own attorney," Hanlon wrote.

Jew, the owner of a Chinatown flower shop, is accused in a Nov. 6 grand jury indictment of five counts of mail fraud, bribery and extortion for allegedly soliciting $84,000 from the owners of eight tapioca drink shops and a dessert cafe seeking city permits.

He also faces separate state criminal charges of perjury, election code violations, voter fraud and providing false documents because he allegedly lived in Burlingame rather than San Francisco when running for office.