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LACHIE Whitfield has been suspended for six months for breaching AFL rules, but the Greater Western Sydney midfielder will be eligible to return in round eight when the Giants play Collingwood.

AFL CEO Gillon McLachlan confirmed the ban on Tuesday afternoon, which has been backdated, also announcing former GWS officials Graeme Allan and Craig Lambert would be handed 12-month suspensions for their roles in the long-running affair.

McLachlan said the bans came with the approval of the Australian Sports Anti-Doping Authority, even though all parties had escaped sanction under the AFL Anti-Doping Code.

The penalties were allocated under conduct prejudicial to the interests of the AFL.

The League is yet to decide whether GWS will be penalised with a loss of draft picks.

"The Commission has ratified that under rule 2.3 that Lachie Whitfield will be receiving a six-month suspension," McLachlan said. 

"Graeme Allan and Craig Lambert will receive 12-month suspensions."

Whitfield apologized for his actions and said he was going through a difficult period at the time of the incident.

"After a long and stressful 18 months, the AFL and I have reached what we believe to be a fair resolution," he said in a statement.

"I was going through a difficult period in my life and was not thinking clearly at the time. I know I should have behaved differently.

"I sincerely apologise to my team mates, coaches and our supporters. I love playing for the GWS Giants and am determined to repay the faith and loyalty they have shown in me."

Following the announcement, Allan released a statement saying that he had resigned from his job at Collingwood.

Under the rules of the ban, the parties will not be permitted to work at any AFL club and they've agreed that they will not participate in any capacity at any other organised sporting competition.

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Asked if there was a chance ASADA would challenge the bans, McLachlan said: "I wouldn’t be announcing this if I didn’t feel there was agreement with ASADA."

AFL legal counsel Andrew Dillon will make a decision on a club sanction with the possibility GWS being stripped of draft picks, however, McLachlan refused to speculate on what might happen.

McLachlan said the officials received longer penalties than Whitfield because they were deemed more liable.

In 2015, Allan and Lambert arranged for Whitfield to stay at Lambert's house in order to avoid the possibility of a drug test out of fear he may fail a drug test.

"He's a 19-year-old kid [Whitfield was 20 at the time of the incident] who took advice from his supervisors or people looking after him so there was a different allocation of responsibility," McLachlan said.

McLachlan differentiated the case facing Whitfield from one of a player accused of taking performance-enhancing drugs.

"There is not one piece of evidence or any allegation of anything to do with performance enhancing drugs. He did not specifically get asked to do a test."

McLachlan said six months was a reasonably significant suspension for the player and proportionately appropriate when measured in relation to the officials.

Whitfield will be banned from the club for four months and will not be able to play for six months.

McLachlan said Allan and Lambert's decision to advise Whitfield to stay at the player welfare's house was "hard to believe".