Eufemiano Fuentes, the Spanish doctor at the centre of the Operacion Puerto doping scandal, has stated that he may be prepared to assist anti-doping authorities, including providing the names of the athletes to whom the blood in bags taken by the police as part of the investigation belongs.

According to a report on Yahoo! Eurosport, Fuentes, who is currently on trial in Madrid on public health charges, told reports outside the court: "If they believe that I am useful and they ask me I would consider it and I would be ready.

"What I don't know is if what I could contribute would be worth anything to them or not," he went on, saying that he had a “mutual collaboration" in mind. "If they want my involvement to include the list they would have it."

While cycling has been the sport most under scrutiny in connection with the scandal ever since it broke in 2006, and a number of riders have provided testimony at the trial, Fuentes has always insisted that cyclists accounted for only three in ten of his clients.

The World Anti-Doping Agency (WADA) has asked to be given access to the evidence, including blood bags, seized under the investigation, so far without success.

However, a lawyer for the Spanish government involved in the case said last week that blood samples, but not the bags themselves, would be released to WADA once the trial is over.

Fuentes and his co-defendants face penalties of up to two years’ imprisonment if found guilty, with closing statements due to begin on 2 April.