WWW- The former mistress of Giant slugger Barry Bonds says he admitted to her that he used steroids. The jolting admission by Kimberly Bell to Fox News Channel’s Geraldo Rivera last night simply added bulk to the suspicions surrounding Bonds and his beefed-up bat.

Geraldo asked: “Did he admit, specifically, to using [steroids] to you?”

“Yes,” Bell answered. “Yes, he did tell me. He told me between ’99 and 2000 that this was something he was doing.”

Bonds has consistently denied in public that he ever knowingly used any form of steroids.

Bell, 35, was on the Rivera program to promote a book she’s writing about her nine-year relationship with the slugger, a book tentatively titled “Bonds’ Girl.”

She said Bonds told her he was using the steroids to help him recover quicker from his injuries.

“He said everybody was – this was something everyone was doing,” said Bell, who states she started dating Bonds when she was 24 and continued to see him until she was 33 – even after he was married.

She also described some of the changes in Bonds’ physique.

“Some of the changes included everything from acne on his back to a great deal of bloating, that he was very concerned about that other people would notice.”

And notice they did. The 40-year-old home run champ put on 45 pounds between his rookie season in 1986 and his benchmark power season of 2001.

That year he broke Mark McGwire’s single-season home run record when he belted 73 dingers.

Bell said she even had to deal with a few bouts of ‘roid rage.

“For example, if he was angry with something I would say or upset, he would be very quick to draw his hand back as if to hit me just so he could see me flinch so that he could laugh about it,” she said.

The mistress went public because she was seeking palimony from Bonds and “he offered me peanuts.”

“He offered me approximately $20,000 to resolve the whole thing and to walk away and sign a confidentiality agreement.”

She did admit that Bonds bought her a new home in Arizona for $157,000 and said no when Rivera bluntly asked: “Kimberly, are you a gold digger, Kimberly?”

“Absolutely not,” she replied.

Bonds has come under fire since details of his federal grand jury testimony in the BALCO case became public at the end of last year.

The seven-time MVP reportedly admitted to ingesting an undetectable mix of performance-enhancing drugs dubbed “The Cream” and “The Clear,” which are, respectively, a cream-based ointment and liquid drops he would put under his tongue.

The bombshell testimony came after years of speculation that Bonds’ added mass did not come naturally.

Bonds, who last season joined Babe Ruth and Hank Aaron as the only major leaguers to hit over 700 home runs, needs just 53 homers to break Aaron’s all-time mark of 755.

Yankee sluggers Jason Giambi and Gary Sheffield also testified before the grand jury that they had used BALCO products.

In Giambi’s first public appearance last week since the testimony leaked, the first baseman dodged all questions relating to his alleged steroid use.