Barry Bonds arrives at the federal courthouse in San Francisco for the second day of his perjury trial. Prosecutors and the slugger's lawyers delivered opening statements on Tuesday. ((Marcio Jose Sanchez/Associated Press))

Barry Bonds admits using steroids during his baseball career, his lawyer told a jury Tuesday. The catch is that Bonds' personal trainer misled him into believing he was taking flax seed oil and arthritis cream.

"I know that doesn't make a great story," Allen Ruby said during his opening statement at the home-run leader's perjury trial. "But that's what happened."

Assistant U.S. Attorney Matt Parrella called such claims "ridiculous and unbelievable" and portrayed Bonds as a liar during his first chance to present the government's position.

And so the crux of the criminal case against Bonds was laid before an eight-woman, four-man jury as the testimony phase of the trial got under way. Bonds has pleaded not guilty to four charges of lying to a grand jury in 2003 when he denied knowingly taking steroids and one count of obstruction.

'All he had to do was tell the truth. That's all, but he couldn't do it' —Prosecutor Matt Parrella

Parrella started the day by saying Bonds lied to the grand jury even though the government promised not to prosecute him for drug use if he testified truthfully.

"All he had to do was tell the truth," Parrella said. "That's all, but he couldn't do it."

Parrella tried to show a deep connection between Bonds and the Bay Area Laboratory Co-Operative, known as BALCO, the Burlingame company at the centre of an international sports doping ring that the grand jury was investigating. Five men, including BALCO's founder Victor Conte and Bonds' personal trainer and childhood friend Greg Anderson, pleaded guilty to steroids distribution after a 2003 government raid on BALCO.

A timeline of Greg Anderson's involvement in the BALCO and Barry Bonds cases.

Feb. 12, 2004 — Named in 42-count indictment in U.S. District Court in San Francisco along with Bay Area Laboratory Co-Operative president Victor Conte and BALCO vice-president Remi Korchemny. Anderson is charged with possession of human growth hormone with intent to distribute, conspiracy to launder monetary instruments and money laundering. He pleads not guilty the following day. 

July 15, 2005 — Anderson pleads guilty to one count of money laundering and one count of steroid distribution as part of an agreement with the U.S. attorney's office.

Oct. 18, 2005 — Anderson sentenced by U.S. District Judge Susan Illston to three months in prison and three months in home confinement.

July 5, 2006 to July 20, 2006 — Imprisoned on contempt-of-court citation issued by U.S. District Judge William Alsup for refusing to testify to grand jury investigating Bonds. Released when grand jury term expired.

Aug. 28, 2006 to Oct. 6, 2006 — Imprisoned on contempt-of-court citation issued by Alsup for refusing to testify to new grand jury. Released because 9th U.S. Circuit Court of Appeals failed to affirm the contempt citation within required period.

Nov. 20, 2006 to Nov. 15, 2007 — After 9th Circuit affirms the contempt citation, imprisoned on contempt-of-court citation for refusing to testify to grand jury. Released on day Bonds gets indicted.

March 22, 2011 — Imprisoned on contempt-of-court citation issued by Illston for refusing to testify at Bonds' perjury trial. Anderson's attorney Mark Geragos vows appeal and tells Illston in court papers that latest jail stint for duration of trial will be a "walk in the park" compared to the previous terms Anderson has served.

On Tuesday, Parrella displayed a photograph taken from a magazine of Bonds, Conte and Anderson and called the trio the "Three Musketeers of BALCO," drawing an objection from Ruby.

Dressed in a dark suit with a light blue shirt, Bonds sat slouched in his chair, his long legs crossed at the ankles and poking out the other side of the defence table, as he watched Parrella tell jurors that a childhood friend of Bonds will discuss watching him inject steroids.

Parrella promised other witnesses will talk about conversations they had with Bonds regarding his steroid use, while others will discuss their deep suspicions.

Ruby, Bonds' lead lawyer, countered by trying to discredit some of the government witnesses scheduled to testify during a trial that is expected to last between two and four weeks.

Defence to try to discredit witnesses

He said at least two prosecution witnesses have axes to grind because of bitter fallouts with the man who hit 762 career home runs, a Major League Baseball record. He also holds the mark for home runs in a single season, with 73 in 2001.

Ruby alleged that Bonds' ex-girlfriend, Kimberly Bell, and former business partner, Steve Hoskins, were "facing the loss of the financial benefit that Barry provided to them over the years" when Bond ended his relationships with them in 2003.

Hoskins and Bell are key government witnesses.

Bell plans to testify that Bonds admitted to her he took steroids. She will also testify to physical and mental changes she says Bonds experienced and that prosecutors attribute to steroid use.

But in a deep baritone, Ruby told the jury that "after the break up Ms. Bell was extremely unhappy," suggesting she has motivation to unfairly denigrate Bonds.

Ruby, a former professional wrestling announcer now with a prestigious law firm, said Hoskins has somewhat similar motives as Bell.

But there is one crucial government witness who won't testify at all — Anderson, who prosecutors allege supplied Bonds with steroids and detailed instructions on how to use them. Anderson was taken to jail Tuesday after he told U.S. District Judge Susan Illston he was refusing to testify against Bonds, who he grew up with in San Mateo County.

Bonds looked away when Anderson and his lawyer Mark Geragos entered the courtroom and again when U.S. Marshals led him away to jail, where he will remain until he changes his mind or the trial ends.

Anderson has been held in contempt before. He served more than a year in prison for refusing to testify in 2006 before a grand jury investigating Bonds.

The judge plans to give the jury an instruction later explaining Anderson's absence from the trial. 

After lunch, lead investigator Jeff Novitzky was called to the witness stand.

Prompted by questioning from Assistant U.S. Attorney Jeff Nedrow, Novitzky recounted for the jury the start of his BALCO investigation. After receiving a tip, and making preliminary internet searches and examining BALCO finances, Novitzky said he began to root through the lab's trash every Monday night for about a year and found incriminating evidence tying famous athletes to BALCO and steroid use.