The Sunday Times reported that Dr Mark Bonar prescribed banned drugs to 150 sports figures including several Premier League footballers.
The paper said Dr Bonar claimed his "clients" included an England cricketer, British Tour de France cyclists, a British boxing champion, tennis players and martial arts competitors as well as footballers.
In the past six years he had treated more than 150 sportsmen from the UK and abroad with banned substances such as erythropoietin (EPO), steroids and human growth hormone, and the performance improvements were "phenomenal", the report added.