Moscow - Russian biathlon star Albina Akhatova on Tuesday claimed she was innocent of doping and vowed to work with officials to clear the matter.

The four-time world champion was one of three Russian biathletes who tested positive for an unnamed substance, believed to be a new generation of the blood booster EPO.

Akhatova, as well as Ekaterina Iourieva and Dmitri Yaroshenko were identified shortly before the start of the world championships in Pyeongchang by the world controlling body IBU as having returned a positive test at the World Cup season-opener in Ostersund, Sweden, in early December.

They left Pyeongchang after having been named.

Akhatova told Russian state TV station Sport that the announcement of her positive test had been a huge shock. "I have not yet recovered from the shock.

"I am not a cheat and have never taken a banned substance."

Akhatova, who won an Olympic gold medal in Turin in 2006, said she and the other two biathletes had met with the head of the Russian biathlon federation Mikhail Prokhorov.

She promised that she would co-operate with the investigation.

Nikolai Durmanov, head of the Russian Anti-Doping Committee, told the same station that he did not believe the athletes to have doped on purpose.

"My personal belief is that the athletes might have suspected something, but rather said nothing," he said, adding that the three biathletes had shown exemplary behaviour since being named.

"They were angry, but not hysterical." (dpa)