"Steve Hoskins' first secretly taped recording did not appear to provide the incriminating evidence that could truly bolster the prosecution's perjury and obstruction-of-justice case against Barry Bonds.

His second one, if admissible, might prove more powerful.

The government on Monday produced a 15-minute tape it contended would show Bonds' former personal assistant and business associate discussing the home run king's use of steroids with orthopedic surgeon Arthur Ting, who operated on Bonds eight times.

Ting severely damaged Hoskins' credibility Thursday when he said they had talked about steroids once and not directly about Bonds using them. Hoskins had testified in the trial's first week that they'd had at least 50 such conversations.

Ting also disputed Hoskins' assertion that the doctor had said the elbow injury that marred Bonds' 1999 season was caused by steroid use. Ting surgically repaired the elbow.

The testimony by a noted medical specialist — albeit one who has twice been put on probation by the Medical Board of California — appeared to sway the momentum toward the defense in a trial in which no side had taken a clear-cut lead.

Tuesday's proceedings might determine whether Hoskins' second recording, which government officials say he found last weekend after previously being unable to locate it, reverses that shift.

The defense raised concerns about the timing of the finding, right after Ting's damaging testimony. Defense attorney Allen Ruby, who called for the tape to be authenticated, questioned its admissibility in court while referring to Hoskins' conduct as "feckless."

U.S. District Court Judge Susan Illston will probably rule on whether the tape is admissible today, when a transcript of its contents is available."