The 25-year-old failed an out-of-competition test in March and, having already been provisionally suspended by the International Cycling Union (UCI), faces a two-year ban from cycling.

His Katusha team released a signed letter from Galimzyanov in which the rider apologises for the offence and also states that he was solely responsible for his doping.

"I recognise a fact of banned substance usage," he said in the letter.

He added: "I would like to draw A PARTICULAR ATTENTION (to the) fact that Katusha Team has nothing to do with what happened. No team member knew and could know about what I did. It was my personal decision and my responsibility.

"I refuse from my right to request and attend the analysis of my B sample."

Katusha have also suspended Galimzyanov and say they "strongly recommends" he co-operates with anti-doping authorities.

Galimzyanov enjoyed his best year in 2011, winning the Paris-Brussels semi-classic and taking a stage and the points jersey at the Tour of Beijing.