Mayor John F. Street (search) acknowledged Thursday that FBI agents confiscated his BlackBerry wireless e-mail unit shortly after police discovered hidden listening devices in his City Hall offices earlier this week.

The revelation came as the Democrat tried to get his re-election campaign back on track two days after the bugs were found, insisting that he has done nothing wrong and has been assured by prosecutors that he is not the target of a federal probe.

The handheld BlackBerry, the mayor said, was taken by an FBI (search) agent just hours after the devices were found during a routine security sweep Tuesday morning.

Street said he gave it to Police Commissioner Sylvester Johnson, who turned it over to the FBI.

The mayor said he asked Johnson about the device -- one of three he owns -- some 15 hours later.

"I said, 'What happened to the BlackBerry?' He said, 'I gave it to them. You'll get it back in a couple days.' I said, 'No problem,'" Street said at a news conference following a Thursday night debate with Republican Sam Katz (search). "I still don't know why anybody is interested in it."

Federal law enforcement sources speaking on condition of anonymity have confirmed that the devices found in Street's office were planted by the FBI, but have declined to say why.

Since the bugging was discovered, Street has denied any knowledge of an investigation and called on the FBI to explain its actions, but he has also drawn criticism from Katz, who said after the debate that he believed "there is substantially more than the mayor has disclosed to the public."

Asked why he had not previously disclosed that agents asked for the BlackBerry, Street said, "Because nobody asked ... I just didn't think about it."

Reports have been swirling for months about investigations into the city's dealings with private companies.

The FBI subpoenaed records from the Philadelphia school district this summer related to the Liberty Academy Charter School, a privately run public school that is scheduled to open in 2004, and was founded by Faridah Ali, the wife of one of Philadelphia's more influential Muslim leaders, Shamsud-din Ali.

A day after the bugs were found in Street's office, FBI agents raided the Philadelphia headquarters of a tax-collection business affiliated with Shamsud-din Ali, Keystone Information and Financial Services.

The company was awarded a no-bid contract in 2002 to collect $605,990 in delinquent city real-estate taxes, according to the city controller's office. According to city records, it was to be paid a percentage of everything it collected.

A man who identified himself as the manager of the company's office in the city's Germantown section said FBI agents arrived at about 11 a.m. Wednesday and spent several hours hauling away records and computers.

The man, who would not give his name, said he didn't know what agents were looking for, or whether it was related to the bugging. He said Shamsud-din Ali, who is an imam at a large mosque and a fixture in city politics, would not comment.

FBI spokeswoman Linda Vizi confirmed that agents had conducted searches Wednesday, but refused to say where or why. Court filings related to the searches are sealed, and the FBI has a policy of not confirming or denying when it is investigating something, she said.

In June, the city was also asked to turn over information on its relationship with Philadelphia Airport Services, an Enron Corp. subsidiary that in 2001 won a $13.6 million maintenance contract at the city-owned Philadelphia International Airport. Earlier this year the company made plans to subcontract $1.2 million of the work to a company founded by Street's brother, but the mayor squashed the deal after critics said it looked too much like nepotism.

Deputy City Solicitor Milton Velez said the city's legal department handed over 25,000 pages of documents. He said he had no information about whether that inquiry was related to the bugging.

City officials confirmed in March that the FBI is also investigating allegations that officials fixed parking tickets in exchange for bribes.

During Thursday's debate, Street said blacks are suspicious that the secret listening devices are somehow related to his re-election campaign. He also said he had reason to believe the bugs "were fairly recently placed." He didn't explain how he knew that.

Katz, who narrowly lost to Street in 1999, rejected those allegations, as has U.S. Attorney Patrick Meehan. Katz suggested Thursday that Street knew more about the bugging than he let on.

"It seems to me from the reports that I've read and heard, that federal authorities have shared information with the mayor. John should tell us all what he and his advisers were told by the U.S. Attorney," Katz said Thursday.