Gatlin went undercover in drug case

Justin Gatlin, the disgraced Olympic 100m champion, worked undercover for the Government as they prepared a case against his former coach Trevor Graham, it was revealed on the fourth day of Graham's trial in San Francisco.

Erwin Rogers, an IRS agent, testified that Gatlin – who has asked the Court of Arbitration for Sport to cut his four-year suspension in half – had secretly recorded phone conversations with Graham, who has pleaded not guilty to lying to federal authorities.

The day's hearing also revealed a first admission of doping from Antonio Pettigrew, who said Graham had encouraged him in 1997 to inject human growth hormone and the oxygen-boosting drug EPO.