Mayor Kenney's appointee to lead the city's Zoning Board of Adjustment resigned Wednesday, three weeks after his home and office were raided by FBI agents investigating the powerful electricians union and its leader, John Dougherty.

James Moylan, a South Philadelphia chiropractor and longtime friend of the union chief, made the decision to step down in consultation with the mayor and his administration, mayoral spokeswoman Lauren Hitt said Wednesday.

"The Mayor believes Dr. Moylan has done an exemplary job as the chair of the [Zoning Board]," Hitt said in a statement. "In the spirit of Dr. Moylan's dedication to public service and his strong character, he has decided that the city cannot afford the ongoing media focus to distract from the board's important work."

Moylan, 53, did not respond to a request for comment Wednesday. A source close to the chiropractor said Kenney asked him to resign over the weekend.

The mayor made the request, the source said, in advance of a scheduled zoning board meeting Tuesday, saying he was concerned that the committee's business would be overshadowed by media attention tied to the Local 98 investigation.

Moylan's resignation was first reported by WHYY.

The search warrants served on his Pennsport house and office last month came shortly after a series of coordinated raids by the FBI on the hall of Local 98 of the International Brotherhood of Electrical Workers, and more than a dozen other sites tied to Dougherty and his close allies, including City Councilman Bobby Henon.

Henon, the majority leader in Council, is a former political director for the union who remains on its payroll.

In each instance, the warrants sought evidence of possible crimes including embezzlement of union funds, intimidation of contractors, and extortion by an unnamed government official.

Sources familiar with the probe say investigators are also examining Local 98's prolific contributions to political campaigns.

Federal authorities subpoenaed finance records last month from Kenney's campaign, which received significant backing from Dougherty and the union during his mayoral bid last year.

Dougherty has denied any wrongdoing, and a spokesman for the union chief declined to comment Wednesday.

The mayor has repeatedly said he has no reason to suspect he or any member of his administration is a target of the probe.

In February, Kenney appointed Moylan, who has worked as a political consultant for Local 98 in the past, to lead the zoning board, a five-member panel that plays a vital role in shaping city development and grants exceptions to building restrictions.

At the time, the chiropractor was serving as president of the Pennsport Civic Association. But his connection to Dougherty spans at least two decades.

A union spokesman has said that it was Dougherty who encouraged Moylan to move his family to Pennsport and set up his practice there in the early 2000s.

More recently, Moylan spoke in Dougherty's defense after a May 2014 fight that broke out between a group of nonunion bricklayers and the union head and other Local 98 members. The rumble happened near the chiropractor's office at 1301 S. Third St.

The bricklayers told police that Dougherty and his members started the altercation. Moylan said he saw as many as five men near Dougherty, with three "coming at him" and two others standing nearby with pipes.

The matter remains under investigation by the FBI and a separate state grand jury probe led by the Attorney General's Office.