The possibility that Rafael Palmeiro's positive test for steroids was caused by a substance given to him by teammate Miguel Tejada was ruled out by a team official Thursday night.

Palmeiro has used the Tejada link as a possible explanation for his positive test, according to sources. But Orioles Executive Vice President Jim Beattie said Major League Baseball's Health Policy Advisory Committee, which oversees steroids testing, has concluded the substance was vitamin B-12.

Palmeiro, 40, named Tejada in both his arbitration hearing with MLB and in the House Government Reform Committee's investigation into whether he committed perjury when he told the committee that he had never used steroids. The revelation was first reported in Thursday's Baltimore Sun.

Beattie said Thursday night that Tejada supplied a sample of what he had given Palmeiro and that tests conducted for HPAC showed it was the vitamin. Beattie said he had been informed of the decision by the commissioner's office, Palmeiro's representatives and Orioles owner Peter Angelos.

"I just found out right now," Tejada said. "I didn't know anything about it. I hope tomorrow I'll find out what's going on. I'll wait until tomorrow. Right now I'm shocked. I didn't give anybody steroids. I was checked out three times and I was clean. I didn't give steroids to anybody.

That didn't bother me because I'm not guilty. I gave him a B-12 shot, which is legal."

When asked when he had given Palmeiro the syringe of B-12, Tejada said, a "long time ago."

A source said Tejada has spoken to committee representatives about the incident, but Tejada denied it.

In his arbitration hearing, sources said, Palmeiro mentioned the B-12 shot but did not offer it as a defense of his positive test. But in an interview during the perjury investigation, Palmeiro did point to the substance as a possible culprit.

Palmeiro's attorneys said in a statement they are "disturbed about the misleading reports being leaked by unnamed sources who claim knowledge of the investigation. Rafael Palmeiro has never implicated any player in the intentional use or distribution of steroids, or any other illegal substance, in any interview or testimony."

Palmeiro and Tejada are both represented by agent Fernando Cuza.

The revelation had led the club to reconsider whether Palmeiro would be welcomed back into the clubhouse for the final homestand of the season.

After speaking with Palmeiro and his representatives, the club thought it best that the first baseman not play again this season.

"I think he will return to Baltimore, but I don't believe he'll be dressing out again this season," Beattie said.

Meantime, after more than a month of investigation, there likely will not be enough evidence to charge Palmeiro with perjury in connection with his testimony in March before the committee, according to a source close to the investigation.

Nor will Palmeiro be exonerated by the investigation, according to the source. Instead, the committee will likely release the results of its investigation and let the public draw its own conclusions.

"The investigation raises a lot of questions but we don't at present have enough facts [to bring him up on perjury charges]," the source said.

The committee, which has also interviewed trainer Richie Bancells, has not concluded whether the substance had any bearing on Palmeiro's test result.

Palmeiro reportedly tested positive for stanozolol, a potent steroid that most experts say can't be taken accidentally. That is perhaps the most puzzling reason why he has now implicated a teammate.

"What it will come down to is either Palmeiro knowingly took steroids or he did something [so] beyond stupidity that I don't know how to describe it," said a source close to the investigation.

Palmeiro returned to his home in Texas on Sept. 5 to recuperate from injuries to his right knee and ankle. The club agreed he could go home to rehab after he was caught using earplugs to block out booing during a game in Toronto on Aug. 30.

Palmeiro had expressed interest in returning for the team's final homestand, beginning Friday against the Boston Red Sox. News that he named a teammate during the investigation may have derailed those plans.

"Put it this way, if you said another teammate gave you something," outfielder Jay Gibbons said, "sometimes you have to look in the mirror and take responsibility for your actions. I'm disappointed, to say the least, if that's true."

Several teammates privately expressed shock Thursday when told the news about Palmeiro. While most had previously supported him, many just shook their heads in disbelief that Palmeiro named one of his teammates. As recently as a week ago, interim manager Sam Perlozzo said he thought Palmeiro's return was a good idea, but he has apparently changed his mind.

"If in fact that was true," Perlozzo said, "then it would probably not be a good idea."

Perlozzo said he spoke to Palmeiro on Wednesday and decided the organization should decide whether Palmeiro's return would be a distraction for the team.

"It's not going away," said Gibbons, the team's player association representative, of the distraction surrounding Palmeiro. "He's not been here and it's not gone away. I don't think it's going to get any better if he comes back."