INDIANAPOLIS -- Eavesdropping devices were found in the office of an Indianapolis deputy police chief believed to be under investigation by the FBI.

Members of the department's Criminal Intelligence Unit were asked Thursday night to conduct an electronics sweep of the office of Deputy Chief of Investigations William Benjamin and found a pinhole camera and a listening device inside a desk drawer, 6News' Jack Rinehart reported.

Earlier this week, Benjamin and his top aide, Maj. Chris Boomershine, gave notice of their intent to petition the Fraternal Order of Police union to provide legal counsel.

Sources told 6News the FBI was investigating a physical altercation between the men and a 31-year state police veteran, Master Trooper Detective Wayne Billings, Aug. 17.

Sources close to the investigation told Rinehart that Billings went to Benjamin's office in plain clothes and made accusations of a personal nature, and that a scuffle ensued when Billings tried to run from the office.

FOP President Sgt. Bill Owensby told Rinehart that one of the interested parties told him that he had confirmed through state police and the FBI that the U.S. Justice Department was looking into the matter, and another source confirmed that the FBI has possession of a tape made by Billings of the altercation.

"I think the only thing we do, then, is wait for notification from the FBI that they want to talk to either one of those two officers … and go from there," Owensby said.

Representatives for Mayor Greg Ballard and Public Safety Director Frank Straub denied asking for FBI help in reviewing the incident.

After the bugging devices were found, Chief Paul Ciesielski issued a statement saying he was going to launch an internal investigation.

"I did not put it there, did not have anyone put it there, nor did the director," the statement read. "I have opened an internal investigation to find out who did."

The mayor's office issued a statement supporting Ciesielski's decision.

FBI spokesman Drew Northern said he can't comment on whether the bugs were the FBI's. He said a lot of other people, including the police internal affairs division, use bugs.

State police said Billings had been placed on administrative duty as they conduct their own internal investigation into the initial altercation.

Ballard planned a news conference at noon Saturday to discuss changes in internal policies at IMPD. A source told 6News that it will not include any personnel or chain-of-command changes.