Essendon Bombers coach James Hird and his wife Tania in August 2013.

James Hird and his wife Tania. Photo: Penny Stephens

Essendon's season-opening clash against North Melbourne threatens to be overshadowed by further claims from the wife of the Bombers' suspended coach James Hird and the appearance of the club's former biochemist Stephen Dank at a charity lunch on Friday.

Tanya Hird revived the explosive allegation that AFL chief executive Andrew Demetriou tipped off Essendon's former chairman David Evans about an investigation into the club's supplements program.

Hird said in an interview on the ABC's 7.30 program that her husband had been made the ''scapegoat'' of the scandal.

While chairman Paul Little and stand-in coach Mark Thompson have been desperate to move on from last season's nightmare and concentrate on football, interviews with James on the club's website and Tanya Hird on the ABC threaten to undermine that aim.

Before leaving for France, where he will attend and elite business school for six months, James Hird this week told Essendon fans that he was ''counting down the days' until he returned to his role as head coach.

And the Hird PR offensive continued when Tania again cast doubt on Demetriou's role in the saga, saying she had taken notes during a key conversation with former chairman Evans.

''Certainly I heard David Evans say to James on speaker phone - I was taking notes, I take a lot of notes - on the 25th of July, David admitted that he said to James go into ASADA and tell the whole truth but don't say what Andrew Demetriou told us,'' she said, referring to the contentious claim that the AFL chief had ''tipped off'' Essendon about the release of the Australian Crime Commission's report into corruption in sport.

''I definitely think James was the scapegoat, in fact we were told that James being the scapegoat was non-negotiable.''

"It wasn't about the integrity of the game by any stretch of the imagination, it was all about the AFL brand.

''James did say in return 'if I'm not asked about it, I won't offer it up, but if I'm asked about it, like anything I'm asked about, I will answer it honestly and truthfully and to the best of my knowledge'.''

Demetriou and Evans have consistently and vehemently denied discussing the confidential ACC report that the AFL had received a few days previously.

''We were told prior to the announcement that there was going to be an investigation into Essendon involving performance-enhancing drugs or supplements,'' Tania Hird said.

''We were told that at a time when we shouldn't have been told that.''

She added her husband only agreed to his 12-month suspension because of bullying from AFL officials.

''He didn't plead to any breach of the player rules, he wasn't found guilty of any breach of the player rules,'' she said.

''In the end it was the threats and bullying of the AFL to the club and to himself. It is a really great game, but at the moment it is an industry where there are a lot of people who are frightened about speaking the truth, about speaking their mind.''

Tania Hird and the couple's children will also leave for France at the end of the month.

Dank is part of a panel at a fundraising lunch at Crown, and so the saga could produce yet more headlines on the day the club is set to start its season.

North's Drew Petrie said there would be no verbal targeting of Essendon players involved in the supplements program, saying it was not in the spirit of the game.

"Our players won't be engaging in any kind of sledging around the ASADA stuff. All other sledging is open season," Petrie said.