Former Arizona Diamondbacks pitcher Jason Grimsley admitted using illegal performance-enhancing drugs and named other players who used banned substances, according to court documents filed by federal investigators.

Grimsley also told investigators that some players use amphetamines "like aspirin."

Grimsley's home in Scottsdale, Ariz., was raided Tuesday by federal agents searching for evidence of drug use, including records of sales, addresses and phone numbers, according to Internal Revenue Service Agent Mark Lessler.

Lesser would not say what agents found. Grimsley, who signed with the Diamondbacks on Dec. 22, has not been arrested and no charges are pending, Lessler said.

The search came weeks after Grimsley received two "kits" of human growth hormone at his home, according to documents filed May 31 in U.S. District Court in Phoenix. At that point, he was confronted by IRS agents, who are leading the steroid investigation, and agreed to cooperate.

In a two-hour interview with federal investigators on April 19, Grimsley named "several other Major League Baseball players by name whom he suspected of using anabolic steroids or human growth hormone," which are illegal under league rules. The names of those players were blacked out on the search-warrant affidavit, which was obtained Tuesday by The Arizona Republic newspaper.

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General manager Josh Byrnes said Grimsley asked for his unconditional release in meetings with team officials Tuesday and Wednesday.

"We accepted his request," Byrnes said. Byrnes would not discuss if Grimsley would be paid the remainder of his roughly $800,000 salary.

In seeking a judge's permission for the search, investigators who cracked the BALCO steroid scandal said Grimsley initially cooperated in the probe. He withdrew his assistance in April, but not before he allegedly made "extensive statements" about illegal drug use, "for the purpose of performance enhancement," according to the court documents.

IRS Agent Jeff Novitsky told the federal judge that investigators wanted to search the right-hander's house for "any and all records showing contact or relationship with any and all amateur or professional athletes, athletic coaches or athletic trainers" regarding illicit drug use and purchases.

According to Novitsky, Grimsley told him the names of other players he believed were using, but the names of those players were blacked out of the court records.

"I have no comment about that and no idea about that," Grimsley told The Arizona Republic on Tuesday, hours before the Diamondbacks played the Philadelphia Phillies.

Diamondbacks managing general partner Ken Kendrick said in a statement the team learned of "this situation late this afternoon," but declined further comment.

Grimsley began his big league career with Philadelphia in 1989 and has pitched for Cleveland, California, the New York Yankees, Kansas City, Baltimore, and Arizona. He has a career record of 42-58 with a 4.77 ERA.

According to court documents, Grimsley failed a league drug test in 2003. Authorities said when he was cooperating, he admitted to using human growth hormone, amphetamines and steroids.

He added that amphetamine use was prevalent in pro baseball, and that it was placed in coffee in clubhouses, marked "leaded" or "unleaded," Novitsky wrote.

After the BALCO investigation, Major League Baseball toughened its testing program for performance-enhancing drugs and included testing for amphetamines for the first time this season.

Word of the Grimsley investigation comes nearly two months after an Illinois-based scientist prominent in the field of sports nutritional supplements pleaded guilty to supplying the Bay Area Laboratory Co-Operative with the performance-enhancing drug known as "the clear."

A federal grand jury in San Francisco is also investigating whether San Francisco Giants slugger Barry Bonds lied under oath about using "the clear." A separate federal grand jury is probing who leaked Bonds' testimony from the BALCO investigation to the San Francisco Chronicle.

So far, the BALCO probe has netted guilty pleas from Illinois-based nutritional supplement scientist Patrick Arnold, BALCO president Victor Conte, Bonds' personal trainer Greg Anderson, BALCO vice president James Valente, and track coach Remi Korchemny.

Baseball banned human growth hormone last year. Like an anabolic steroid, it builds muscle mass and helps athletes recover faster from injuries.

The Associated Press contributed to this report.