San Francisco ? Barry Bonds’ personal trainer was set to be released from prison today, his attorney said, the same day the term of the grand jury investigating the baseball star was to expire.

It was unclear if Greg Anderson’s expected release would have any bearing on whether indictments were handed up against Bonds. He was being investigated for possible perjury and tax evasion.

Attorney Mark Geragos told The Associated Press late Wednesday that he was certain Anderson would be released from jail at noon today. Geragos declined to say how he knew it.

Anderson was held in civil contempt and sent to federal prison earlier this month for refusing to testify to the grand jury investigating Bonds. Anderson was to be held until he agreed to testify or the term of the grand jury expired. Geragos has said in the past that his client would not testify.

Prosecutors could choose to impanel a new grand jury after the current one expires today, meaning Anderson’s status could be in jeopardy again.

Anderson likely holds the key to whether perjury charges could stick against Bonds, who testified in 2003 that he thought substances given to him by the trainer were arthritis balm and flaxseed oil.

Authorities suspected Bonds was lying and that those items were “the clear” and “the cream” – two performance-enhancing drugs tied to the BALCO, the lab exposed as a steroids supplier to top athletes in baseball, track and other sports.

“Obviously, they think they need Greg to prove perjury,” Geragos said.

Allegations of steroid use long have plagued Bonds, who passed Babe Ruth in May to become second only to Hank Aaron on the career home run list. They intensified in late 2003, when he testified before the original Bay Area Laboratory Co-Operative grand jury, which took testimony from about two dozen athletes.

Without the trainer’s help, prosecutors still could indict Bonds on charges alleging he failed to pay taxes on money made through sales of autographs and other memorabilia. They also could seek to extend the grand jury’s term to put more pressure on Anderson to cooperate, or convene a new panel and put Anderson back in jail. There’s also the chance Bonds might be indicted on perjury charges without Anderson’s testimony.

“I don’t think Barry has violated any laws. Under our system, if the government is going to point a finger at him, the government better be well prepared to,” said Bonds’ attorney, Michael Rains. “I will do everything in my power to make sure that Barry gets a tenacious and effective defense.”

Federal prosecutors declined to comment Wednesday.

Anderson was one of five men convicted in the steroids scandal surrounding BALCO. He was sentenced to three months behind bars and three months of home confinement in October after pleading guilty to money laundering and steroid distribution.

He was found in contempt of court and jailed again July 5 for refusing to testify in the Bonds probe.

Federal prosecutors say they need Anderson, in part, to interpret calendars that seem to spell out Bonds’ schedule for using performance-enhancing drugs. The calendars were seized by investigators from Anderson’s house in 2003.

Geragos says Anderson must be released when the grand jury’s term expires today, even if prosecutors succeed in extending the panel’s investigation.

But former federal prosecutors said authorities likely will try to keep him locked up.

“That’s simply because he hasn’t served that much time in jail,” said Jonathan Howden, who left the U.S. Attorney’s office earlier this year after 25 years as a prosecutor. “Under normal circumstances, the judge would find that he is still lawfully subject to the contempt order.”

Separately, Geragos has launched an effort to get his client freed based on a tape-recorded conversation that Geragos says was made illegally in the spring of 2003 by government investigators. On the tape, Anderson allegedly discusses Bonds’ illegal drug use with an unidentified athlete.

“Mr. Anderson allegedly makes numerous remarks regarding baseball’s steroids testing, Barry Bonds’ use of an undetectable performance-enhancing drug to beat drug tests, and Mr. Anderson’s own alleged steroid use,” Geragos said in a court filing.

Geragos is demanding that the government disclose the contents of that tape.