Paul Doyle said he received an email from the trainer indicating that former 100-meter record-holder Asafa Powell was given a combination of 20 supplements and injections, none of which are banned by the World Anti-Doping Agency, The New York Times reported Tuesday.
The Times said it obtained the email but it could not be independently authenticated as being sent by trainer Christopher Xuereb
Powell and 100-meter Olympian Sherone Simpson confirmed on Monday that they had recently tested positive for the banned stimulant oxilofrine.
They were among five of Jamaica's international athletes that officials said had positive drug test results.
Doyle said he believed Xuereb's combination was responsible for the positive drug tests for Powell and Simpson, part of Jamaica's 4x100-meter relay team at the 2004 games in Athens.
"We're trying to figure out what went wrong, and it was pretty obvious to us where we needed to look," Doyle told the Times.
Italian police raided the hotel in the northeastern city of Lignano Sabbiadoro Monday where Xuereb and the Jamaican sprinters were staying.