More than 180 members of the Australian Defence Force were sacked in the past year for misconduct ranging from the use of prohibited substances to serious sexual offences, new figures show.

Among those forced out of the military was the alleged ringleader of the so-called Knights of the Jedi Council, Hastings Fredrickson, who has appeared in a Sydney court to face six charges of using a carriage service to offend.

Eighty-nine dismissals from the army involved the use of prohibited substances.

More than 50 others had their service careers terminated for other forms of misconduct and unacceptable behaviour, while a further 15 were sacked for civil offences.

The vast majority of members sacked in the past year came from the Australian army, with 138 of its members dismissed by the ADF.

Twenty-six Navy and 18 Air Force members were sacked.

These dismissals or "involuntary separations", as Defence calls them, were not necessarily related to abuse, a Defence spokesman said.

The military aspirations of former Australian Defence Force Academy cadet Daniel McDonald were finally extinguished in November last year.

The cadet at the centre of the Skype scandal was found guilty in the ACT Supreme Court of committing an act of indecency and using a carriage service in an offensive manner.

Fredrickson and more than a dozen others allegedly shared explicit videos and emails boasting about their sexual exploits with unsuspecting women.

An initial Defence investigation cleared them of wrongdoing but Fredrickson, a former commando turned reservist, was later charged by NSW Police.

He was issued with a termination notice by Defence in July last year, which he did not challenge.

His military career was terminated in September.

Sacking prior to court case completion 'grossly unfair'

Fredrickson's lawyer Peter Woodhouse would not comment on the specifics of the case but said, in some instances, Defence has been too hasty to sack some members.

He described as "grossly unfair" any decision to cut short someone's military career before a case had run its course in the civilian system.

"It's something that we're seeing more frequently than we used to," Mr Woodhouse said.

"We're concerned that it might be coming at the expense of giving due process and procedural fairness to these military personnel that are under investigation."

Mr Woodhouse said some of those whose military service is terminated struggle to find other work.

"Many military people are career military and they don't have any other skills to fall back on," he said.

"When their career in the military is terminated, they're lost effectively."

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