"UK Anti-Doping has reviewed the evidence presented to us by The Sunday Times and it is of grave concern and of significant interest," UKAD chief executive Nicole Sapstead said in a statement.

"We have opened an investigation and are taking the necessary steps to corroborate the evidence and investigate it further."

The investigation by the Sunday Times, conducted with German broadcaster ARD/WRD, said three men had been arrested by Kenyan authorities last week, having reviewed the film footage.

The newspaper said the two doctors claimed to have given a British athlete a series of EPO injections in preparation for a major race.

An associate of the doctors said three other Britons were among about 50 athletes he had supplied with prohibited substances.