TENNIS:Tommy Haas will undergo tests today to establish whether he was poisoned during Germany's Davis Cup semi-final tie in Moscow in September, as he has claimed. Tests on blood and hair samples are to be carried out by a toxicologist in New York, according to the German number one's agent, after the player claimed that he had been poisoned.

Haas (29) is to fly to New York today for the tests, the results of which are expected to be made public. "I would like to know whether it's possible to conclude that I was poisoned or to prove it at all," he said. "Whether the tests will be conclusive or not, I don't know but I don't want to leave any stone unturned. I want to know what is wrong with me and what possible consequences it might have."

Haas, who admitted he was still feeling off-form, added: "My stomach sometimes suddenly does wild things."

Alexander Waske, his friend and fellow player, who broke the scandal after alleging on the basis of information from a Russian informant that Haas had been poisoned, said it would be difficult to expect conclusive results.

"If you don't know which poison you're looking for, it's presumably going to be very difficult to find anything," he said.

The International Tennis Federationsaid it was taking the allegations "very seriously" and that its Davis Cup executive director, Bill Babcock, was to lead an investigation. "If the allegations turn out to be true, that would be terrible. An investigation is beginning right away," said the ITF's spokeswoman Barbara Travers.

Haas added more details to his claim yesterday, telling DPA that he had vomited not only during the Davis Cup in Moscow but before a tournament in Lyon at the end of October which he was forced to quit because of stomach problems. "It's possible it's all linked and that these were the long-term consequences," he said.

Waske said he told Haas a few days ago what a Russian sports manager had told him. "He came up and said: 'Man, Alex, that was a close thing in Moscow. It was bad that they poisoned Tommy.'"

He added that, when he had pushed the man for more information, he was told: "Alex, believe me, I was in Moscow. There are people at work and, when they say they poisoned Tommy, then they poisoned him."

Waske continued to refuse to reveal the identity of his informant apparently either to the authorities, to Haas or to the Davis Cup team head, Patrik Kuhnen.

Haas became ill during the Davis Cup semi-final between Russia and Germany at the end of September which the German team lost 3-2. He told Bild he had been forced to spend "six hours hanging on to the toilet. I'd never felt so dreadful in my life. It made me feel really scared."

Asked to speculate how and when a poisoning might have occurred, he said: "I am always the only one of us who orders a pudding or a latte macchiato after supper. As no one else among us was struck down, they must have - if it happened - done it there."

The Hamburg-based German Tennis Association said it was taking a strong interest in the allegations but so far they remained purely speculative.

Last night the Russian prosecutor general's office said it had not received a complaint from Haas. A spokesman said it could only investigate if Haas formally contacted the Russian authorities.

Russia's tennis federation dismissed Haas's allegations as "fantasy" and said it did not believe there was evidence that the German had been poisoned. It also pointed out the German federation had reached the same conclusion.

Meanwhile, former Scotland Yard detectives working for the governing body of men's tennis flew to Frankfurt to interview Nikolay Davydenko's wife and brother about the match-fixing allegations against the world number four.

The investigators are leading the Association of Tennis Professionals' inquiry into the Russian's retirement through injury from a second-round match against the Argentinian world number 74 Martin Vassallo Arguello in the Poland Open in August.

The online betting exchange Betfair declared void $7.3 million (€5 million) of bets on that match after identifying suspicious patterns of gambling.

Davydenko has always denied any match-fixing.