WASHINGTON, D.C. -- U.S. Rep. Tom Davis, a Republican from Virginia, told The Associated Press his House committee will investigate whether baseball slugger Rafael Palmeiro committed perjury when he told Congress earlier this year that he never took steroids.

The House Government Reform Committee wants the documents that explain the positive drug test that has put the Baltimore Orioles first baseman on ice for 10 days. Palmeiro has pledged his full cooperation to Congress, and has agreed to release details of the test. That would include the results, dates of the tests and other relevant facts.

Palmeiro's the highest-profile baseball player suspended for flunking a steroid test. He'd testified before the committee in the spring that he had never taken steroids.

A person with knowledge of baseball's testing program told The Associated Press that Palmeiro tested positive for a powerful steroid not found in dietary supplements.

Report: Palmeiro Used Potent Steroid Stanozolol

Palmeiro reportedly used the powerful anabolic steroid stanozolol -- the same substance that Olympic sprinter Ben Johnson tested positive for in 1988.

The New York Times reported on its Web site Tuesday night that a "person in baseball with direct knowledge of the sport's drug-testing program" said Palmeiro tested positive for stanozolol, also known as Winstrol.

The Times' source refused to be identified because MLB's testing policy prohibits anybody in baseball from disclosing information about test results without authorization.

The 40-year-old Palmeiro was suspended by Major League Baseball on Monday for a first-offense positive test. He appealed the punishment, but it was denied.

The stanozolol revelation flies in the face of denials of steroid use by Palmeiro, who implied that his positive test was either a mistake or an unwitting minor infraction.

"I'm sure you will ask how I tested positive for a banned substance," Palmeiro said in a statement. "As I look back, I don't have a specific answer to give.

"I hope that all MLB players and kids will learn from what has happened to me," he added. "I have never intentionally used a banned substance, but I unfortunately wasn't careful enough."

However, stanozolol does not come in dietary supplements and is one of the most popular performance-enhancing steroids on the market, so unwittingly taking it seems unlikely. In the Times' report, New York University professor Dr. Gary Wadler characterized stanozolol as more than a minor substance.

"Potent is the word I would use," Wadler said.

Palmeiro testified at Congressional steroids hearings in March, pointing at the panel and angrily denouncing accusations by former teammate Jose Canseco that he had used steroids. In Canseco's book "Juiced: Wild Times, Rampant 'Roids, Smash Hits, and How Baseball Got Big," Canseco wrote that Palmeiro used steroids when the two played with the Texas Rangers.

"I have never used steroids. Period," Palmeiro told Congress.

Palmeiro likely won't face perjury charges because his positive test was taken several weeks after the hearings.

Just last month, Palmeiro became only the fourth player in baseball history to record 500 home runs and 3,000 hits, joining Hank Aaron, Willie Mays and Eddie Murray. He reached the milestone hit on July 15 in Seattle.

The Baltimore Sun reported for its Wednesday editions that Palmeiro knew that he had failed a drug test while he attempted to reach 3,000 hits. The newspaper reports a source familiar with the timeline indicated Palmeiro tested positive for a steroid in May and appealed the ruling in secret arbitration proceedings in June.