Dr Mark Bonar operates from a clinic in central London. He says the athletes he treats with banned substances have achieved ‘phenomenal’ improvements in their performance

A British doctor has been secretly filmed describing how he prescribed banned performance- enhancing drugs to 150 elite sportsmen, including Premier League footballers.

An investigation by The Sunday Times has found that Dr Mark Bonar charges sports stars thousands of pounds for illicit drug programmes.

Yesterday, the culture secretary, John Whittingdale, ordered an inquiry into the taxpayer-funded UK Anti-Doping (Ukad) watchdog, which was given evidence about the doctor’s doping activities two years ago, but failed to take any action to stop him.

Bonar, 38, who is based at a private London clinic, made a series of extraordinary disclosures in meetings with undercover re­porters which lay bare for the first time the depth of the drugs cheating culture within British sport. He claimed:

• His network