Contador and Basso said to be among Operacion Puerto witnesses when trial begins in January

Alberto Contador and Ivan Basso are among 35 witnesses who will be called in the Operacion Puerto trial when it opens in Madrid on 28 January next year, nearly seven years after the blood doping scandal broke, reports Spanish newspaper El Pais.

The trial, which will be presided over by Julia Patricia Santamaria Matesanz, is expected to last nearly two months.

Dr Eufemiano Fuentes, former doctor to the Liberty Seguros-Würth team which counted Contador and Michele Scarponi among its riders at the time and who was seen as the mastermind of the alleged doping ring, is one of six people accused, each facing a jail sentence of up to two years if found guilty, although certain charges against some of the accused carry a penalty of four years.

Also in the dock on charges relating to crimes against public health are two other doctors, Fuentes’ sister Yolanda and José Luis Merino Batres, plus former team managers Manolo Saiz and Vicente Belda and trainer Ignacio Labarta.

Operacion Puerto hit the headlines in May 2006 when officers from the Guardia Civil raided a number of addresses in Madrid and seized bags of blood.

The scandal led to a number of riders being placed under investigation, many of them, such as Jan Ullrich - sanctioned earlier this year for his part in the affair - being withdrawn by their teams from that year’s Tour de France.

Astana-Würth, the new name of the Liberty Seguros-Würth team following a mid-season change of sponsor after the insurance company withdrew its backing, also succumbed to pressure and pulled out of the race.

Basso and Scarponi were among riders to receive bans connected to Operacion Puerto, but while a number of Spanish riders including Contador were implicated in the scandal, no rider from that country was ever sanctioned by the national anti-doping authorities.

Alejandro Valverde, not named as a potential witness in El Pais, did eventually receive a two-year ban after Italian Olympic Committee CONI determined that DNA from a sample taken from him when the Tour de France visited Italy was a match for a blood sample seized during Operacion Puerto.

CONI banned the Spaniard from competing in Italy and the World Anti-Doping Agency and UCI successfully applied to the Court of Arbitration for Sport to have that ban extended worldwide.

While it was cyclists who were the main focus of official investigations and press interest in the wake of Operacion Puerto, the trial could be an uncomfortable prospect for athletes competing in other sports.

Fuentes himself has said that his clients included leading Spanish football teams and tennis players, while among those called as witnesses are the former Kelme rider Jesus Manzano, who has claimed that he saw football players from La Liga clubs at the doctor’s clinic.