Olympic and world cycling champion Paolo Bettini supplied sacked German cyclist Patrik Sinkewitz with doping products, according to television reports here on Wednesday.

Quick Step rider Paolo Bettini of Italy crosses the finish line to win the third stage of the Tour of Spain cycling race between Viveiro and Luarca, September 3, 2007. [Reuters]

Sinkewitz, 26, was dismissed by T-Mobile during this year's Tour de France when abnormal levels of testosterone were found in his blood during a pre-race drugs test.

The German later admitted he had used 'Testogel' patches to help aid recovery.

But according to reports on German channel ZDF, Sinkewitz is quoted in a document as naming 2004 Olympic road champion and defending world road champion Bettini, plus retired Italian Davide Bramati, as his suppliers.

"I got the Testogel from Italian riders and I can also name them, they were Davide Bramati and Bettini," he is quoted as saying.

Told of the television accusations, Bettini - who was on his way to Stuttgart from Venice airport - immediately called Sinkewitz to quiz him.

According to ANSA news agency, Sinkewitz denied ever having named Bettini.

Bettini is reported as telling his former team-mate over the telephone: "If as you say you didn't say what has been reported then issue a denial immediately."

"If you have said what has been reported then you will have to be held responsible."

Sinkewitz and Bettini were team-mates at professional teams Mapei and Quick-Step, before the German switched to T-mobile in 2005.

He wants to help doping investigators as a principal witness in order to reduce his ban, which is expected to be two years.

Bettini meanwhile has given the International Cycling Union (UCI) a headache over his refusal to bow to requests for a DNA sample.

The UCI attempted to guarantee a scandal-free Tour de France this year by demanding all participating riders to sign a pledge promising not to dope.

Threatened with having to pay a year's salary if caught doping, the peloton was also asked to submit a blood sample to the ruling body to rule them out of any involvement in the ongoing 'Operation Puerto' doping affair in Spain.

Bettini is set to defend his rainbow jersey at the men's world championships road race on Sunday, but has so far refused to sign the UCI's pledge.

He claims handing over a blood sample is akin to giving up one's basic human rights.