Dr Patrece Charles-Freeman, executive director at Jamaica Anti-Doping Commission (JADCO), said last night that an investigation had been launched into reports that at least two Jamaican athletes have tested positive for a banned substance.

Charles-Freeman told The Gleaner that JADCO would make a statement on the matter "soon".

She, however, refused to confirm reports that two Jamaican athletes who have been named to the team heading to the World Championships in Berlin returned positive tests.

It was unclear up to press time whether the alleged positive tests were returned at the National Trials in June or at overseas meets.

"JADCO has no comment at this time. We are investigating the rumour out there," she said. "We will be making a statement on the matter soon."

A source close to the matter who did not wish to be identified told The Gleaner that athletics interests were bracing for a disturbing announcement.

At least 40 to 45 tests were conducted at the trials. The tests were sent to a lab in Montréal, Canada.

The Gleaner has also learned that the positive tests do not involve any of the the island's top male sprinters.

Dr Herb Elliott, a member of JADCO, said he heard about the rumour. "We are waiting to get some information."

Three Jamaicans have returned positive doping tests over the past five years. The most recent case involved sprinter Julien Dunkley.

Dunkley was dropped from the list of Jamaican athletes set to compete at the 2008 Olympics in Beijing, China.

Sprinters Steve Mullings and Patrick Jarrett also tested positive for banned substances.