Barry Bonds' fellow star Giambi details steroid use

Oakland Athletics' Jason Giambi hits a two-run home run, his second of the game, in the ninth inning against the Toronto Blue Jays in an American League baseball game in Oakland, California, May 9, 2009.

SAN FRANCISCO (Reuters) - Baseball star Jason Giambi, testifying at home run king Barry Bonds' perjury trial, said on Tuesday that he used illegal anabolic steroids obtained from Bonds' personal trainer.

Giambi, a hulking slugger who was the American League Most Valuable Player in 2000, described how he started using the steroids after meeting trainer Greg Anderson at an all-star baseball game in Japan.

"I was picking Greg's brain as to what kind of training Barry was doing, was he lifting weights, what was he doing in the gym," Giambi said. "Barry was a great athlete. I just wanted to continue my career so I wanted to get information from him."

He said that Anderson subsequently sent him packages containing steroids he called "the clear and the cream," explaining that the cream was testosterone, and the clear was epitestosterone. The package included a syringe with injectable steroids, which Giambi said he used.

Giambi said Anderson told him Major League Baseball tests were designed to detect the ratio of these two hormones and by raising the levels of both, he could increase their testosterone level without testing positive for illegal steroids.

Bonds has pleaded not guilty to charges he lied to a grand jury about whether he knowingly used the same substances. His case is the latest in a years-long U.S. investigation into the use of performance-enhancing drugs in professional sports.

The charges stem from his 2003 appearance before a U.S. grand jury investigating the Bay Area Laboratory Co-Operative, or BALCO, whose head has pleaded guilty to dispensing steroids to professional athletes.

KEY 2004 REPORT

A report in 2004 that Giambi had admitted steroid use in the BALCO investigation helped spark a controversy about performance-enhancing drugs in baseball and led to a probe into the sport by George Mitchell.

The eventual Mitchell Report found over 100 players had used such drugs, though their names were not disclosed.

Giambi was the MVP while with the Oakland Athletics and later was a star for the New York Yankees. He was named to the league all-star team five times.

Dressed in a blue suit and striped tie, the bearded Giambi said he used the drugs for a few months before abandoning them.

Earlier on Tuesday, the head trainer of Bonds's team, the San Francisco Giants, testified that Bonds put on muscle mass, sprouted acne and refused to be weighed by the team.

Trainer Stan Conte estimated that Bonds gained 10 or 15 pounds of lean muscle mass around 1999 or 2000. Prosecutors allege that weight gain and the acne were caused by Bonds' steroid use.

Bonds had told the BALCO grand jury he did not knowingly use steroids or growth hormones and said he never questioned the flaxseed oil, vitamins, protein shakes and creams Anderson supplied him.

In 2001, he hit 73 home runs, a single-season record that still stands. In 2007, his last season in the league, he broke Hank Aaron's 33-year-old record of 755 career home runs.

(Editing by Peter Henderson and Philip Barbara)