ADELAIDE coach Brenton Sanderson has backed his assistant Dean Bailey to clear his name amid an investigation involving the former Melbourne coach for tanking while at the helm of the Demons.

Sanderson said he was so confident his assistant would escape charge that the Crows hadn't bothered establishing a contingency plan should Bailey be sanctioned by the AFL.

"Dean's under investigation at the moment, but in the 12 months he's been working with us he's been outstanding and I'm really thankful for the support he's given me," Sanderson said.

"I know the investigation's close to coming to an end, I'm really confident that Dean's name's going to be cleared, so at this stage no, there's no plan B."

The AFL is investigating claims the Melbourne Football Club tanked in 2009 to deliberately lose matches in order to gain a priority pick at that year's NAB AFL Draft.

Bailey has remained steadfast that he did the best thing for the club by testing players in different positions towards the end of the season.

Sanderson also described spot betting in the AFL as "out of hand", after suggestions from the Australian Crime Commission that the League had become vulnerable to match fixing.

While downplaying organised crime's ability to fix matches, Sanderson said it was smaller spot bets that posed the largest danger.

"It's very hard to get to enough players to fix a match in AFL, but it's not hard to get to one player for spot betting," he said.

"I think the AFL maybe have to regulate a little bit of the spot betting now just to avoid players getting involved with any of this organised crime."

Sanderson remained skeptical of the Australian Crime Commission's initial findings that suggested widespread use of performance enhancing drugs in Australian sport and warned vague claims could seriously damage the AFL's brand.

He said he believed "99.5 per cent" of the AFL was clean, including the entire Adelaide Football Club, and that assertions blanketing it as a league with much to fear had already hurt "brilliant people".  

"Initially it was widespread and now it's not widespread, so I guess we're waiting for the clarification of that exactly what the issue is," he said.

"At a time where we're really trying to get good sponsorship, good companies around our brand, this has just really hit it for six.

"I'm sure we'll get through it, but to hear other sporting codes from around the world commenting on Australian sport now is disappointing because I just know that we are clean.

"I think 99.5 per cent of our industry is doing things well and doing things above board and legal.

"There's some brilliant people working in this industry you know who, unfortunately, have got a little black mark against their name at the moment."

Harry Thring is a reporter for AFL Media. Follow him on Twitter: @AFL_Harry.