ESSENDON CEO Xavier Campbell says he is disappointed information relating to the WADA investigation continues to be leaked but maintains he is confident in the players' position.

Speaking after the AFL CEO's meeting in Werribee, Campbell said he thought it was unfair on players when confidential information entered the public domain.

"My frustration comes from a process that is meant to be confidential that has continually been plagued by leaks throughout," Campbell said.

"I think that is unfair on the players and has (happened) right throughout. The players have done nothing but respect the process, they continue to do that, and I think it's just not fair on them."

Earlier, Campbell haddismissed the significance of claims that tests commissioned by the World Anti-Doping Agency have shown elevated levels of the banned substance thymosin beta 4 in samples of two Essendon players from 2012.

Fairfax reported the frozen urine samples of two players from 2012 showed levels of TB4 that were abnormally high when tested in Germany.

The AFL’s anti-doping tribunal cleared the 34 current and past Essendon players of having received the substance, which is found naturally in small amounts within the body.

WADA will reportedly point to the test results as proof that the players were administered with doses of TB4 by sports scientist Stephen Dank.

In a statement on the Bombers' website, Campbell said he maintained total belief in the players' innocence.

"Nothing that has come from the submission has altered my view or confidence in the players' position," Campbell said.

"WADA claims there are apparently results which show a level of TB4 which is higher than they might have expected would be present naturally in the human body.

"It is clear that WADA does not know what the results mean. There were no supporting documents or evidence in the WADA brief and there are real doubts as to the significance of these claims."

WADA is set to appeal against the AFL tribunal's verdict in November at the Court of Arbitration for Sport in Sydney.

Either party is able to introduce new evidence at the hearing.