Essendon chairman Paul Little has slammed the AFL for making assertions against the club and its players that are not supported by any evidence.

Little was speaking following the release of an AFL statement detailing charges against the club, coach James Hird and other personnel.

He said the fact the AFL had known for six months that anti-obesity drug AOD-9604 was not banned, but allowed questions to hang over the club and it players was "reprehensible".

"Justified by the evidence gathered during the investigation, the AFL makes assertions that are simply not supported by the evidence," Little said.

"The AFL has known since February this year that one of the substances at the heart of the investigation was not banned.

"That the AFL has known this for six months but let question hang over the club and our players is reprehensible.

"The AFL is determined to punish Essendon as though they were drug cheats."

Meanwhile, Hird accused the AFL of subjecting him to a "trial by media" with the release of the charges against the club.

Hird says he and his lawyers were given only minutes' notice of the AFL's statement and suggested that certain actions by the league were in breach of due process.

"The release by the AFL of a letter by Dr Bruce Reid to me that formed part of the confidential ASADA investigation is in breach of due process," Hird said.

"The letter released in isolation is designed to damage my reputation."

With regard to the charges against himself and the club, Hird said his position had not changed.

"My position is the same today as it was yesterday and in previous weeks, that is I will contest these charges," he said.

"These charges are denied and will be vigorously contested once the AFL actually provides due process. The announcement by ambush confirms the AFL is running an agenda which continues to call into question its impartiality.

"In this frenzy of releases and press conferences today, the AFL remains silent about its knowledge that since February 2013 of the fact that AOD-9604 not being a banned substance.

"Throughout the course of this exercise I have been denied natural justice and today's ambush is just another example of that."

More to follow.