Dean Robinson has not been interviewed by Ziggy Switkowski or his investigation team.

Dean Robinson has not been interviewed by Ziggy Switkowski or his investigation team. Photo: Sebastian Costanzo

A legal threat from the high-performance coach stood down by Essendon in February has delayed the release of the internal probe into the club's supplements scandal.

Dean Robinson has launched a legal challenge against the release of the Ziggy Switkowski report on the basis that any public findings or recommendations could deny him natural justice.

It has emerged that Robinson, stood down on February 5 by Essendon's football boss, Danny Corcoran, has not been interviewed by Switkowski or his investigators over his role in the so-called ''irregular practices'' that took place at the club during 2012.

Robinson and Essendon remained at odds late on Tuesday over the sensitive issue of whether Robinson had been medically fit to undergo any form of interrogation by Switkowski or his team.

Initially, the former Geelong, Gold Coast and Essendon fitness coach was unwilling to meet the club's lawyers because his health reportedly had suffered as a result of the scandal, with Essendon players still facing suspension if found guilty of taking banned substances.

It remained unclear on Tuesday night whether Switkowski had attempted more recently to interview Robinson. Neither Essendon chairman David Evans nor Robinson's lawyer, David Galbally, QC, would clarify the standoff.

Evans released a statement through the club that said: ''The club cannot discuss the report until the recommendations are made public, which we look forward to doing as soon as possible.''

Galbally refused to comment.

It is understood that Essendon was attempting to interview Robinson following the legal challenge, but on Tuesday night the two parties remained in a standoff over the state of the inquiry, which reportedly has been completed.

Switkowski's key findings and recommendations were due to be released on Wednesday, but the Bombers have postponed that for at least 24 hours and could be forced to wait until next week before making any public announcements.

While Essendon reportedly has told the AFL it believed Robinson was refusing to be interviewed on the basis he was medically unfit, the high-performance coach was questioned weeks ago by Australian Sports Anti-Doping Authority investigators and the AFL's Abraham Haddad.

The ASADA interviews were spread over three days and under certain conditions for medical reasons.

Robinson was less than halfway through a lucrative three-year contract, estimated to be worth about $1 million, when the club stood him down on the day it announced it was reporting itself to the AFL and ASADA.

While Robinson has connections to sports scientist Stephen Dank, the reasons for his departure have not been made clear by the club. He remains on full pay and it is not known whether he plans to take legal action against the Bombers or whether the club intends to settle his contract.

Robinson has spoken publicly only once - to the Seven Network last month. In a brief interview at Galbally's book launch, Robinson said the ordeal had had a detrimental effect on his health.

While key club officials are likely to face sanctions as a result of the Switkowski findings, AFL chief executive Andrew Demetriou said last week the league would not act to punish the club until the ASADA investigation was complete.

While Essendon and the players' union remain optimistic players will not be suspended, the club could be hit with a variety of sanctions, including the loss of premiership points.