By CHRIS STEVENSON -- SLAM! Sports
 PENRITH LAKES, Australia -- A busy signal could be all that's preventing another drug scandal at the Olympic Games.

 The canoe competition was rocked Friday by allegations in a Bulgarian newspaper that three Buglarian canoeists tested positive for banned substances in July at their national championships.

 The International Canoe Federation is trying to investigate the claim, but has so far run into a brick wall. The Bulgarian Olympic Committee has said it has no knowledge of any positive tests and attempts to contact the Bulgarian anti-doping commission by telephone have been unsuccessful because the line is always busy.

 "For three days I've tried to get an answer by fax from the anti-doping commission, but up to now there has been no answer," said Ulrich Feldhoff, the ICF president.

 "Yesterday we tried to contact them by telephone, but the two numbers given to us are continuously engaged."

 Feldhoff said the ICF's hands are tied at this point.

 "I've given the material to the International Olympic Committee because we cannot act just on the basis of a newspaper article," said Feldhoff. "We can only act on the basis of an official document and this must be answered by the Bulgarian anti-doping committee."

 Ivan Slavkov, an IOC member and the chef de mission for the Bulgarian team wrote back to the ICF that "the Bulgarian Olympic Committee has not received any official information from the Bulgarian Anti-Doping Commission. It is rather surprising that your request is based on a newspaper article."

 To complicate matters, said Jan Verstuyft, the chairman of the ICF medical committee, the laboratory in Bulgaria where the testing was done is not sanctioned by the IOC, so it's not clear if the results would stand up.

 According to the article, the athletes tested positive for a diuretic and the results were announced by the anti-doping commission at a press conference a couple of weeks ago in Bulgaria.

 A diuretic is usually used by people looking to lose weight quickly, but can also be used as a masking agent.

 "It can be used to dilute the urine to make it impossible to detect other substances," said Verstuyft.

 He said Bulgarian athletes have been tested both in and out of competition and since they arrived in Sydney and there has been no notification of a positive test involving canoeists.

 If it turns out the reports are true, medal winners would have to return their medals.

 "Athletes who manipulate their performance will have to give their medals back," said Feldhoff. But other athletes, who might have lost out on opportunities to advance to finals to Bulgarians "have no new chance," he said.