Controversial sports scientist Stephen Dank has reportedly said he will sue ASADA and its chief executive Ben McDevitt for defamation in the wake of the Essendon supplement saga.

Dank told Fox Sports News his lawyers will be taking action against the anti-doping agency and McDevitt after ASADA said it was considering an appeal against the AFL's Anti-Doping Tribunal's decision to clear 34 former and current Essendon players of all charges.

In a Wednesday press conference, McDevitt accused Dank of sending mixed messages about whether there were any records of what injections Essendon players were administered.

"No party has disputed that Stephen Dank played a central and critical role, the lead role in administering the injections," McDevitt said.

"Stephen Dank has publicly stated that extensive records of the injection regime were kept but, throughout this investigation, no such records have been found.

"Curiously, Mr Dank, in a statutory declaration provided to ASADA, in response to a disclosure notice, declared he had no documents to produce.

"All the evidence that I have seen probably would indicate if there were records, they would be shambolic and chaotic."

McDevitt said that ASADA had no powers to force sports scientist Stephen Dank to testify.

The AFL Anti-Doping Tribunal is expected to make a decision on Dank's role in the supplements program some time after Easter.

McDevitt said those findings would not determine whether ASADA lodges an appeal but they might have some influence.

"We eagerly await that component from the tribunal because Stephen Dank was the alleged architect here and so it will be very interesting to see what the findings are, and what the reasons behind those findings are from the tribunal," he said.

"It will certainly enable us to make a more informed decision [on our appeal]."

Sorry, this video has expired ASADA chief executive Ben McDevitt addresses the media

Earlier in the week, Dank saved his sharpest barbs for ASADA in the wake of the tribunal absolving the 34 Essendon players.

"They've been very, very poor in their conduct, execution and understanding of this whole investigation," he said.

"The players never took anything that was illegal or anything that was against the WADA-prohibited list.

"The players were not guilty of anything. I'm very happy for the players."