The race to be Mayor is in turmoil in Philadelphia after at least two electronic listening devices were found in the private offices of the Democrat incumbent, John Street.
The FBI confirmed its agents planted the bugs, but refused to say when they were installed, or why. Members of Mr Street's campaign claim they are part of a Republican dirty tricks campaign.
Philadelphia is four weeks from voting day and the race between Mr Street, a first-term Mayor, and his Republican challenger, Sam Katz, is extremely tight. The men were pitted against each other at the last election four years ago and Mr Street won by only 10,000 votes.
Mr Street said he had received private reassurances from FBI officials that he was not the subject of a criminal investigation. But his aides suspect the bugs may be part of an effort by his opponents to smear him.
"The timing of the discovery of these listening devices seems incredibly strange," said Frank Keel, the Street campaign spokesman. "Do we believe the Republican Party, at the federal level and state level, is pulling out every stop to get Pennsylvania in 2004? Absolutely. Is the Republican Party capable of dirty tricks? That is well documented."
Concern has also been raised by the Governor of Pennsylvania, Ed Rendell. "I think given this extraordinary situation with four weeks to go, it is incumbent upon the FBI to say why they planted the device," he said.
The FBI has denied that it would have helped in any politically motivated plot to harm Mr Street.
The Mayor's tenure has been marred by corruption scandals. The Mayor's office has faced claims it fixed parking tickets of allies and helped secure a $13.6m public-works contract for a firm connected to the Mayor's brother. During the campaign, an aide to Mr Street has been charged with threatening a landlord for offering to rent space to the Katz campaign. In August, a man threw what appeared to be an unlit firebomb into Mr Katz's headquarters.Reuse content