A congressional committee is investigating whether another Orioles player gave Rafael Palmeiro a substance that might be linked to the first baseman's positive steroid test, according to people familiar with the investigation. The scenario of Palmeiro receiving a substance from a teammate was described by Palmeiro himself in closed-door proceedings before a three-member baseball arbitration panel earlier this year as he presented his steroid defense, one source said. A second source confirmed the account and that Palmeiro had identified the teammate by name. The sources declined to be identified because the congressional investigation is ongoing. The House Government Reform Committee -- as part of its investigation of whether Palmeiro lied six months ago when he testified that he never used steroids -- has been trying to determine whether Palmeiro's story has merit. The committee is interviewing people who, sources said yesterday, include members of the Orioles -- including Palmeiro himself -- and Richie Bancells, the club's head athletic trainer.