SAN FRANCISCO — Twenty federal agents raided the home of the mother-in-law of Barry Bonds' personal trainer on Wednesday.

Madeleine Gestas and her daughter Nicole Anderson, the trainer's wife, are the target of a tax investigation that the lawyer for Greg Anderson said is aimed at pressuring the trainer to testify at Bonds' upcoming trial.

Bonds, baseball's career home run leader and a seven-time MVP, has pleaded not guilty to charges he lied to a federal grand jury in 2003 when he denied knowingly using performance-enhancing drugs.

"Even the mafia spares the women and children," said Anderson's lawyer, Mark Geragos.

Lead prosecutor Matthew Parrella didn't immediately return a telephone call Wednesday.

Geragos said he believes the raid was in response to his refusal to tell prosecutors whether Anderson would testify. Geragos said he ignored a letter faxed to his Los Angeles office Monday by prosecutors that asked about Anderson's plans for the Bonds' trial.

Anderson served more than a year in prison for refusing to testify against Bonds before a federal grand jury. Geragos said that on the day after her husband was released from prison, Anderson's wife received a so-called target letter informing her that she was under investigation.

Geragos said Anderson received a government subpoena last week demanding his testimony at the March 2 trial. Geragos declined to say whether Anderson would testify. If Anderson refuses, he could be sent to prison again.

The New York Times, citing an anonymous source, reported Thursday that prosecutors have evidence that links Bonds to the use of performance-enhancing drugs other than the "cream" and the "clear" — the designer substances that have become synonymous with the Bonds case.

A person who has reviewed the prosecution's evidence said that authorities detected anabolic steroids in urine samples linked to Bonds, according to the Times.