SAN FRANCISCO -- A noted scientist in the sports nutritional supplement world accused of supplying the Bay Area Laboratory Co-Operative with the performance-enhancing drug known as "the clear" is expected to plead guilty Friday in federal court here.
A San Francisco federal grand jury indicted Patrick Arnold in November of conspiring with BALCO founder Victor Conte to distribute the once-undetectable substance tetrahydragestrinone.
Since he was charged with three counts of illegally distributing performance-enhancing drugs, Arnold has maintained his innocence. But a source familiar with the case said Arnold will likely plead guilty to at least one charge in exchange for the others being dropped.
The source spoke on condition of anonymity Thursday because the proposed plea deal was confidential.
Arnold's anticipated plea comes as a grand jury is investigating whether Barry Bonds, the San Francisco Giants outfielder, lied about using "the clear" to another grand jury that investigated the BALCO lab more than two years ago.
So far, the BALCO probe has netted guilty pleas from Conte, Bonds trainer Greg Anderson, BALCO vice president James Valente and track coach Remi Korchemny.
Arnold was snared after federal agents raided his Champaign, Ill., lab last year.
Giants athletic trainer Stan Conte, no relation to Victor Conte, Bonds' surgeon Arthur Ting and Anderson have been summoned to testify in front of the Bonds grand jury.
According to leaked excerpts of Bonds' testimony reported in the San Francisco Chronicle, Bonds told the BALCO grand jury he used a "clear" substance and a cream given to him by Anderson.
Bonds, who is approaching Babe Ruth's home run record, testified that Anderson informed him the substances were the nutritional supplement flaxseed oil and a rubbing balm for arthritis.
Arnold, 39, was known for introducing the steroid precursor androstenedione to the United States. Nicknamed "andro," the chemical came to public attention in 1998 when St. Louis Cardinals slugger Mark McGwire said he used it when he broke baseball's single-season home run record.
The indictment against Arnold alleged he trafficked in performance-enhancing drugs that were designed to avoid detection by sporting leagues, including the U.S. Anti-Doping Agency, Major League Baseball and the National Football League.
Bonds hit his 711th career home run in San Francisco's 9-7, 11-inning loss to New York on Wednesday, placing him three homers behind Babe Ruth for second on the career list, trailing Hank Aaron (755).