The 34 players involved in the Essendon supplements saga will know within days whether they are finally free of the controversy.

The deadline for the World Anti-Doping Agency to appeal to the Court of Arbitration for Sport against the AFL anti-doping body's decision to clear the players is set to expire.

WADA had a three-week window to appeal from when the Australian Sports Anti-Doping Authority announced on April 20 that it would not present a fresh case before the AFL's appeal board and would hand any decision on further action to the anti-doping body's world governing body.

A WADA spokesman said on Saturday the independent review was continuing and a decision had yet to be made.

"We are still within our appeal window until early next week," the spokesman said.

The AFL and Essendon hope WADA opts to not appeal, but ASADA chief executive Ben McDevitt was angered by the anti-doping tribunal's decision to clear the players of being administered the banned drug, thymosin beta 4.

McDevitt visited WADA's head office in Montreal on May 1 but the spokesman said the reason was not specifically to discuss the Bombers' issue.

"Mr McDevitt attended a WADA-hosted National Anti-Doping Organisation (NADO) ad hoc working group meeting ... this was not a specific meeting regarding the matters in Australia," the WADA spokesman said.

"Mr McDevitt was joined by representatives from eight other NADOs for the meeting. The aim of the meeting was to look at practical ways to enhance partnerships and communication between NADOs, WADA and the anti-doping community. This included looking at challenges, best practices and effective strategies for NADO co-ordination under the revised World Anti-Doping Code."

If WADA was to appeal before the Court of Arbitration for Sport, the saga would extend for several months, with the 34 current and former Essendon players remaining under the threat of suspension.

Any appeal would be "de novo", meaning the entire case would begin afresh and would not be restricted to what had already been argued. However, lawyers believe that unless WADA can secure new evidence, it would also fail.

Lawyer and Fairfax Media columnist Darren Kane, analysing the case, recently said ASADA's case, which relied on "a dumpster full of circumstantial evidence such as emails, intercepted text messages, possibly bogus invoices, transcripts and newspaper scrapbooks" fell "so horrendously short of the mark".

"Unless a visit from the magical evidence genie is impending, it is impossible to understand how WADA will do any better," he said.

Regardless of WADA's decision, Stephen Dank, the architect of the supplements program, will appeal the 10 guilty findings against him made by the AFL's anti-doping tribunal, despite his not having attended and or given evidence in the initial hearing. This appeal will be heard from June 9.