The key witness in the Essendon doping case has warned ASADA not to back him into a corner by forcing him to give evidence in the AFL scandal.

Shane Charter said the Australian Sports Anti-Doping Authority is unlikely to get the information it needs if it compels him to give evidence.

“I’ll do what’s legally required, however you back someone into a corner and you’re probably not going to get a positive outcome,” he said.

The anti-doping body is seeking subpoenas in the Victorian Supreme Court to compel witnesses Charter and Nima Alavi to give evidence against Essendon.

If the pair do not give evidence it will blow a hole in ASADA’s case.

Charter said ASADA only asked him to appear as a witness three weeks ago, some 18 months after the saga began, and had accused it of making changes to the statement he made to authority.

“I come from a sporting background and I don’t mind having a fight here and there, and so this is round one over in the courts today,” he said.

“If they get the ability to subpoena, good luck with round two.”

Charter, 46, was speaking outside Melbourne Magistrates Court where he is due to face charges of trafficking and possessing steroids and possessing a schedule four poison.

He said his role in the ASADA case and the criminal charges laid against him were linked.

“I believe there’s a correlation,” he said.

“I think when they look at the evidence today, what would be a good outcome is (Victoria Police) drop my charges, maybe ASADA drop their charges, everyone has an early Christmas.”

The AFL anti-doping tribunal is scheduled to start hearing the charges against 34 current and past Essendon players on December 15.

If found guilty, the players are facing suspensions of up to two years.

The application to force Mr Charter and Nima Alavi to give evidence won’t be heard until five days before hearings are due to begin.