SAN FRANCISCO - Barry Bonds' former mistress, at the centre of the government's perjury investigation of the slugger, said Monday she will discuss the couple's relationship in the November issue of Playboy magazine.

The Playboy article, accompanied by a nude pictorial of Kimberly Bell, is scheduled to hit newsstands Oct. 1. The 37-year-old Bell said the article will cover details of her relationship with Bonds that she told a grand jury investigating the perjury allegations in 2005.

"The opportunity was there, and I took it,'' she told The Associated Press in a phone interview Monday. The photo shoot "was one of the most liberating experiences of my life.''

Bell testified before the grand jury that Bonds once told her of his steroid use in 2000 and that he implied he started taking the performance enhancing drugs in response to Mark McGwire's pursuit of the single season home run record in 1998.

"He was very envious of Mark McGwire,'' she said from her San Jose home. "He never said that was the reason, but I know it was.''

Bell testified about that conversation as well her relationship with Bonds, which lasted from 1993 to 2003. She also said Bonds gave her US$80,000 in cash to buy a house, the proceeds of which allegedly came from a paid autograph session that authorities also are investigating as going unreported to the Internal Revenue Service.

Bonds' lawyer, Michael Rains, could not be reached for comment late Monday.

The term of the grand jury investigating Bonds' steroids testimony appears to have been extended because the San Francisco Giants left fielder's personal trainer remains jailed. Greg Anderson was to be released last Thursday, the end of the grand jury's term, unless the term was extended.

The U.S Attorney's office has declined to discuss the grand jury proceedings. But one of Anderson's lawyers, Paula Canny, believes the term was extended.

"Greg's still not out,'' she said.

Bell said she has not been called before the grand jury again, but declined to say if she has spoken with federal investigators since.

Bell's appearance in the magazine can't help the government's case against her former lover.

Defence lawyers are widely expected to argue that Bell was a woman scorned because of Bonds' decision to marry another woman during their relationship. Her appearance on Playboy may only add fuel to the defence's case.

Bell said the photo shoot boosted her confidence. She declined to say how much Playboy was paying her.

"If I had more self-esteem when I was younger,'' she said, "I wouldn't have been caught up with such a rotten man.''