THE Australian Sports Anti-Doping Authority (ASADA) says an Australian Federal Police and Deloitte investigation has found no one within their organisation was responsible for leaking sensitive information to the media.

During the peak of ASADA's investigation into players in the NRL and AFL, several sensitive documents were published in the media last year that related to Essendon Football Club.

It was enough to force outgoing ASADA chief executive Aurora Andruska to call in the AFP and Deloitte to go over the organisation with a fine-tooth comb.

"There were media suggestions, and from other quarters, that the organisation was leaking," Andruska told a Senate estimates hearing on Wednesday.

"I brought in Deloitte and the AFP to make examination of any leaks occurring, and there were none. ASADA was not leaking."

Andruska said the investigation examined all communication that had been made and received by the organisation over the past several years.

She said she could only speculate where the leaks came from, and when invited by the senators to do so, replied: "I don't think that's an answer I'd give".

The investigation into Essendon's supplements programs has been completed, but ASADA is reviewing its evidence meaning players could still be issued with infraction notices.