Haas pulled out before his match against Mikhail Youzhny with a suspected stomach virus, and Russia won both reverse singles matches in Moscow on Sept. 23 to beat Germany 3-2 and reach the Davis Cup final.

German teammate Alexander Waske later said he was told by a Russian who manages numerous athletes that it was poisoning, not a virus. Waske didn't say who the manager was.

"Following inquiries, the ITF has concluded that there is no medical information or other evidence whatsoever to support recent speculation concerning the medical condition of Tommy Haas during Germany's Davis Cup semifinal tie against Russia," the federation said. "There will be no further comment on this subject."

The 13th-ranked Haas has undergone various medical checks to try to determine the nature of his illness.