The New South Wales Department of Fair Trading says it knew of problems at Australian Aerial Patrol since December, but say they lack the power to put volunteer group into administration.

The future of the shark patrol charity, based in the Illawarra, looks in doubt amid a series of investigations into fraud and misappropriation of funds.

Aerial Patrol is being investigated by police and government authorities for hundreds of thousands of missing dollars which allegedly cannot be accounted for.

Just two weeks ago, Aerial Patrol's main sponsor, Bendigo Bank, withdrew funding after the resignation of the chief pilot and engineer.

In a statement released to the ABC on Friday, the Department revealed it conducted a review of the shark patrol charity which showed ''significant internal governance and control issues''.

However, it said it was powerless to act and shifted the blame to the volunteer committees tasked with overseeing the organisation.

The Department was provided with the forensic accounting report compiled by accountant Ian Fargher, which detailed a number of allegations, including large restaurant bills, invoices for work never done, and the disappearance of $750,000 in alleged drug money.

''The report very clearly states that the documentation on which the forensic report is based is incomplete,'' the Department stated.

It concluded that there were insufficient grounds to appoint an administrator for Australian Aerial Patrol.

Meanwhile, the man at the centre of the allegations, long-time general manager Harry Mitchell, protested his innocence in a media interview over the weekend.

Mr Mitchell said the restaurant bills were to reward volunteers, and invoices for traffic reports never conducted were an agreed way to increase his salary from $35,000 per year to $70,000 per year.

He said that was fair recompense for working at the patrol "24/7".

The ABC revealed last week that the National Crime Commission was seeking $750,000 from Aerial Patrol, believed to be the proceeds of a drug deal paid by Fairy Meadow pilot, Bernhard Stevermuer, who was interested in buying NSW Air and Aero V, the patrol's commercial arms.

The sale fell through when Stevermuer pleaded guilty to dealing in property suspected of being the proceeds of crime. He was later sentenced to 19 months in jail.