AFL investigators have focused on the final three minutes of Melbourne's after-the-siren loss to Richmond in 2009 and have even questioned whether players deliberately fumbled the ball as part of an explosive probe into tanking.

Documents, as part of an 800- page report, distributed to lawyers of the Melbourne Football Club, confirm serious questions have been raised about the coaching of Dean Bailey in round 18 and the club's interchange rotations through the season.

Suspicions over the Demons' motives were raised through a number of positional moves in a game in which Richmond's Jordan McMahon marked on the final siren and booted the winning goal.

The decision by the Demons to send lumbering ruckman Paul Johnson to full-back on small forward Nathan Brown has been a focus of questioning, as revealed in the documents. Brown has said previously he was surprised to have been manned by Johnson.

The report, which fills two folders, also investigates the round-17 loss to Sydney at Manuka Oval, when the Demons made eight pre-match changes, and the round-22 loss to St Kilda, which ensured the Demons of the coveted top two picks in the national draft.

"They are the games that just keep on coming up, especially the Richmond one," a source close to the Demons said.

"The last two or three minutes of that Richmond game is what they [investigators] really centre on."

The Demons took the lead with three minutes remaining, with the ball trapped in the Tigers' forward line in the final seconds until McMahon marked alone at centre half-forward and slotted through the winning goal.

It is understood those interviewed have denied claims the players fumbled on purpose in the final minutes.

Lawyers for all parties on the Melbourne side maintain that the AFL, led by its investigators Brett Clothier and Abraham Haddad, cannot prove anything in this regard and have vowed to fight any charges.

The documents also question the Demons' interchange rotations. There are suggestions the Demons had a high number of rotations in their four wins for the season, but cut numbers in other games.

Under then AFL draft rules, the Demons would get picks one and two following two successive seasons of managing no more than 16 premiership points.

The Demons averaged 85 rotations a game in 2009, although this was as high as 93 up to round 15 – the day they beat Port Adelaide for their third win of the year and jeopardised hopes of a priority pick. The AFL average for rotations was 92.

The Demons had 82 rotations in their round-four win over the Tigers, 98 in round 14 in a win over West Coast, and 94 a week later in the win over the Power.

In the contentious loss to the Tigers three weeks later, the number of rotations would plummet to 47, the fewest by any team that season, with 49 against North Melbourne the next week.

However, investigators have queried why they would then have 99 interchanges in a win over Fremantle in round 20 at the MCG. This was by far their biggest number after round 15. The Demons had only 56 rotations in the round-21 loss to Carlton, a match in which it is believed club fitness and medical staff have been questioned about certain events, including the game-ending injuries of defender Matthew Whelan and forward Ricky Petterd.

It is the round-18 loss to the Tigers that has dominated questioning, for there were several moves, later branded experimental, that added to suggestions the Demons did not want to win. These included premier midfielder James McDonald being sent to the back line, key defenders James Frawley and Matthew Warnock spending most of the afternoon up forward, and regular forward Brad Miller used as a midfielder. Forwards Colin Sylvia and Russell Robertson were left in the VFL. Brock McLean, who sparked the investigation, did not play.

The Demons have until the end of the month to respond to the claims.

Bailey is facing three allegations: bringing the game into disrepute, tampering with the national draft, and not coaching to his utmost in 2009.

Chief executive Cameron Schwab and former football manager Chris Connolly are facing charges of bringing the game into disrepute and tampering with the draft.

As per AFL Regulation 19 (A5), tanking is defined as "a person, being a player, coach or assistant coach, must at all times perform on their merits and must not induce, or encourage, any player, coach or assistant coach not to perform on their merits in any match – or in relation to any aspect for the match, for any reason whatsoever".