Baseball superstar Barry Bonds used performance-enhancing steroids for at least five years, a new book by two sports reporters is set to claim.
Bonds has shattered previously untouchable records
Bonds injected, swallowed and rubbed on a variety of chemicals, changing from a player known for speed and skill to a raw powerhouse, the authors allege.
The book, Game of Shadows, is based on more than 1,000 pages of documents and more than 200 interviews, they claim.
Bonds has always denied wrongdoing and has refused to comment on the book.
"I won't even look at it. For what?" he asked reporters when they questioned him about it, Sports Illustrated magazine said in articles about the book on its website.
The San Francisco Giants slugger holds the record for hitting the most home runs in a season - 73 - and is closing in on the record for the most home runs ever.
His trainer, Greg Anderson, has been convicted of steroid distribution and was sentenced to three months in prison last year.
Anderson was sentenced to three months in prison
Anderson was associated with a disgraced San Francisco firm called Balco, which was raided by anti-doping agents in 2003.
Its founder, Victor Conte, was imprisoned for supplying athletes with illegal performance-enhancing drugs.
Mark Fainaru-Wada and Lance Williams - the authors of Game of Shadows - claim Balco kept day-by-day, drug-by-drug records of the chemicals that Bonds took starting in 1998.
They say that in 2001, the year he broke the record for most home runs in a season, he was taking six substances: designer steroids known as the Cream and the Clear, insulin, human growth hormone, testosterone decanoate (known as Mexican beans) and trebolone.
The writers claim that Bonds urged his trainer to keep him on the chemicals continuously, going without the one-to-two-week break many athletes on steroids take in order to allow their bodies to recover.
'Not the Olympics'
The player was already outstanding when he allegedly began to take the chemicals in 1998, but, the book claims, was jealous of the attention paid to two power hitters duelling to set a new home run record.
He began taking illegal substances, gained weight, and began hitting home runs at nearly twice the rate he had before.
Sports Illustrated has made much of the allegations
Bonds testified at the Balco trial under a grant of immunity for drugs cheating.
He said his trainer had given him substances which he took without knowing what they were or that they were banned, Fainaru-Wada and Williams claim.
After his testimony became public, he said he had done nothing wrong.
"You're talking about something that wasn't even illegal at the time.... Man, it's not like this is the Olympics," he said.
The publication of book excerpts on the Sports Illustrated website has prompted an online debate about whether Bonds' records should be allowed to stand, removed from the books, or marked with an asterisk.
Some correspondents have argued he should not be eligible for the Hall of Fame, while others have pointed out he has never been convicted of wrongdoing.
Major League Baseball has been struggling to formulate a workable anti-doping policy as previously untouchable power-hitting records have been broken repeatedly in recent years.