As part of a wide-ranging probe of corruption in Alaska politics, the FBI secretly taped over 100 phone calls involving indicted GOP senator Ted Stevens.

The revelations were contained in court filings made last night by Stevens' attorneys. Some of the FBI's recordings of phone conversations had already been made public during the corruption trials of other Alaska politicians, but the number of calls involving Stevens had not previously been known.

Stevens faces charges that he lied about gifts worth more than $250,000, including renovations to his home, that he received from Bill Allen, an oil contractor.

Stevens' attorneys appear likely to argue that the calls should not be admitted into evidence. They write in the filing that only conversations relating to people or topics named in a warrant can legally be recorded by the FBI, and Stevens was not named as a target. The FBI did not tap Stevens' phone, but did tap the phones of several contractors in the case.

McClatchy notes another strategy being pursued by the defense:

His lawyers also continued to press their case for throwing out the indictment based on the speech-or-debate clause of the U.S. Constitution, which bars government prosecutors from using speeches and legislation introduced by members of Congress as evidence. Prosecutors said that evidence protected by legislative immunity granted by the Constitution was not shown to the grand jury that ultimately indicted Stevens.

Jury selection for the trial begins September 22, and the trial itself starts two days later. Stevens is also facing a tough re-election fight against Anchorage mayor Mark Begich, a Democrat.