The opaque web has raised serious concerns about the flight's insurance coverage and the legal entity that will eventually be held to account for the February crash.

At least three large law firms are preparing legal action on behalf of the victims.

Separate entities owned the plane, operated it, flew it, maintained it and chartered it.

Adding to the confusion, the B200 Super King Air was registered to yet another company just a week before it crashed into the Essendon DFO shopping centre.

Paul O'Brien, managing director at AVMIN, one of Australia's largest charter-flight bookers, says involving six different companies in a single flight blurred the lines of responsibility.

"Accidents will occur, but there have to be some procedures in place that ensure that if there is, you are covered insurance-wise," he says.

Mr O'Brien said many small charter companies held the minimum insurance required, which is $725,000 per passenger according to the Civil Aviation Safety Authority.

Another aviation source said the mandatory amount was "laughable".

The question over who was responsible for the flight is still being investigated by the Australian Transport Safety Bureau.

Records show the owner of the plane VH-ZCR is Bendigo based-company BB1544. Its sole director is businessman Christopher Richards.

Dr Richards is also behind the company MyJet Aviation Services, which transferred the operation of the plane to Australia Corporate Jet Centres (ACJC) in the weeks leading up to the crash.

The operator is in charge of maintenance and airworthiness of a flight, according to the Civil Aviation Safety Authority.

Dr Richards declined to comment.

ACJC was told by CASA hours after the plane had crashed that it had been registered in its name five days earlier.

An administrative bungle over an incorrect credit card expiry date recently led to a legal fight over ACJC becoming the registered operator.

"This is the flavour of general aviation in this country, it's a hotchpotch," said aviation safety expert Neil Hansford.

It remains unclear whose air operator's certificate was being used to conduct the flight. The air operator's certificate authorises someone to fly for "hire and reward" but also carries potential liability.

ACJC has claimed Max Quartermain's company Corporate & Leisure Aviation leased the plane from MyJet and flew it under his own air operator's certificate.

Mr Quartermain's certificate was still current when the plane smashed into the shopping centre, however MyJet's authorisation had expired.

The flight itself was booked through tour-company GolfSELECT, which declined to comment last week. Golf trips to King Island and then Barnbougle Dunes in Tasmania cost $2500 per person, according to its website.

It is understood yet another company called Interair was hired to maintain the plane. The company continued to service the plane despite the administrative bungle over its registered operator.

When the families will actually get answers about what went wrong is unclear.

The Australian Transport Safety Bureau is behind on most of its investigations, finalising just 30 per cent of complex cases within 12 months in 2015-16 ??? well below the legislated requirement of 90 per cent.

Mr Hansford says the delay was related to Australia taking a lead role in the complicated MH370 investigation and the compounding effect that has had on the rest of the agency's work.

Flight MH370 disappeared on March 8, 2014 while flying from Kuala Lumpur to Beijing.

"It was a massive task, the Americans would have had problems coping with a crash of that type," he says.

What may hasten the Essendon investigation is the involvement of US authorities like the Federal Aviation Administration, which has been brought in to help.

Lawyers are also circling what could end up developing into a multimillion-dollar lawsuit.

There is also the potential for US attorneys to become involved, after the death of high-profile Texan lawyer Russell Munsch and three other wealthy Americans in the crash.

Maurice Blackburn's aviation law expert Joseph Wheeler says the questions over who was in charge of the plane would need to be resolved to ensure someone was made liable.

One of the consequences of the crash and the subsequent administrative battle may be a streamlining of CASA's administrative processes, he says.

"The families will not be left without remedy just because of some administrative or other confusion," he says.