Fresh details have emerged surrounding an AFL investigation into claims that Melbourne tanked during the 2009 season.

A 7News exclusive revealed investigators are focusing on three of the Demons' matches during that season: their round 15 win against Port Adelaide, their round 18 loss to Richmond and their round 22 loss to St Kilda.

The AFL have constructed an 800-page report on why it believed the Demons tanked in 2009, with Dean Bailey, CEO Cameron Schwab and director of football Chris Connolly reportedly set to face charges.

It is believed though that charges won't be laid until mid February. There have also ben threats of legal action should the AFL find the club or any individuals guilty of charges.

7News has uncovered investigators are alleging irregularities which they believe indicate the club was not trying its best to win matches.

Then senior coach Bailey has been particularly implicated, with questions being asked as to why he left the coaches box before Melbourne's clash with Richmond had finished.

Investigators also queried bench rotations, and strange match-ups including Matthew Warnock and James Frawley being sent forward and ruckman Paul Johnson playing on former Tiger goalsneak Nathan Brown.

Richmond ended up winning the game with a kick after the siren from Tiger midfielder Jordan McMahon.

Questions were also raised over Melbourne's win over Port Adelaide, with investigators claiming they have vision of Schwab criticising players after the match.

The Dees led for most of the match before eventually winning by 11 points.

Melbourne's round 22 loss to St Kilda has also been called into question, with investigators probing match-ups on Saint star Nick Riewoldt and why Demon livewire Liam Jurrah was left out of the match.

It is believed former Demon president, the late Jim Stynes, has not been implicated in any of the investigations.

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