SAN FRANCISCO -- San Francisco Giants star Barry Bonds and sprint champion Kelli White were among the 40 athletes subpoenaed by a federal grand jury in the budding steroid scandal, Agence France-Presse reported Saturday.

According to the report, Victor Conte, the president of under-investigation BALCO Laboratories, told the San Jose Mercury News and the San Francisco Chronicle that his top clients are being asked to testify about tetrahydrogestrinone, or THG.

Conte told the newspapers that seven professional football players and five Major League Baseball players were among those compelled to testify in hearings on the West Coast that are expected to begin next week.

"I do know that Barry has received a subpoena," Conte wrote in an e-mail to The Chronicle. "There are at least seven NFL players that I know of, plus at least four professional baseball players, that have received a subpoena. Most of the other athletes are from track and field. My understanding is that 40 elite Olympic and professional athletes have been subpoenaed to appear before a grand jury."

In the June issue of Muscle & Fitness magazine, Bonds enthused about Conte's physical fitness regimen and nutritional advice, saying, "I'm just shocked by what they've been able to do for me."

Bonds' agent, Scott Boras, told The Chronicle last week that the investigation "really doesn't involve Bonds."

White confirmed to the Mercury News that she was subpoenaed but denied a role in the steroid inquiry.

"I really don't have anything to do with that situation," she said. "That's not me."

The doping scandal erupted earlier this week when news broke that three track and field athletes who flunked drug tests had been subpoenaed to testify before a federal grand jury that is investigating what one anti-doping official calls "an international doping conspiracy."

The three athletes were tested at the U.S. Track & Field Nationals in Palo Alto, Calif., in June and one of the athletes was a client of BALCO. The controversial nutritionist boasts of a roster of professional and Olympic sports stars as customers, and one source close to the case said Thursday that "the names I've heard are some of the biggest names in sports."

"I know of no other drug bust that is larger than this involving the number of athletes involved," anti-doping official Terry Madden, director of the U.S Anti-Doping Agency, told The Associated Press on Friday. He refused to reveal the names or genders of the athletes, or to be more specific about how many had tested positive.

On Thursday, Madden identified Conte as the alleged supplier of the previously undetected steroid THG, which was detected in the three athletes -- a charge Conte has denied.

"What we have uncovered appears to be intentional doping of the worst sort," Madden said during a news conference. He called the case "a conspiracy involving chemists, coaches and certain athletes to defraud their competitors, and the American and world public who pay to attend sporting events."

In September, agents for the Internal Revenue Service raided BALCO, in Burlingame, Calif., carting out boxes of records and raising suspicions that federal agents are interested in its finances. By then, Madden said, they already had been told about USADA's findings. Besides Bonds and White, BALCO's clients include, Bill Romanowksi, and Olympic stars Marion Jones and Tim Montgomery.

Conte said Thursday that BALCO was not the source of the substance.

"In my opinion, this is about jealous competitive coaches and athletes that all have a history of promoting and using performance-enhancing agents being completely hypocritical in their actions," he said.