The illegal trade of birds into and out of Australia is going virtually unchecked, with two sweeping government investigations failing to prosecute the smugglers they identified.

The investigations revealed the role of sophisticated networks of criminals trading eggs of native parrots with those of exotic parrots from South Africa, Singapore and the Philippines.

But despite having some of the toughest penalties in the world for wildlife crime, up to 10 years in jail and $100,000 fines, the alleged perpetrators were not even charged.

The previous national manager of investigations with the Australian Customs Service says that is because wildlife investigations are poorly resourced.

Richard Janeczko, who retired from Customs in 2009, says the illegal trade in birds is alive and well.

But he says the lack of prosecutions is because of the poor quality of evidence obtained during the investigations.

"I believe with a bit more resources effort and equipment those people could be successfully prosecuted," he said.

"There's no point in having all those great penalties without anyone who's actually going to find the crime, do the paperwork, take them to court and prosecute people."

These pigeons were being smuggled in this man's tights. ( Australian Customs Service )

Species extinction

The two investigations were carried out between 2004 and 2009 and involved state and federal authorities.

Their failure has seen the illegal trade in birds expand and the traders become more brazen.

Mr Janeczko says if nothing changes, some of Australia's most unique wildlife could become extinct if diseases are introduced with the exotic wildlife.

"I think these animals will die out," he said.

"If you look at things that happened to some Australian animals, including the Tasmanian devils, that's a good example about introduction of diseases by wildlife smugglers.

"It can wipe out a whole range of animals and once they’re gone you can’t bring them back."

An example of the dangers was documented last year when two diseased pigeons were smuggled into Australia.

They carried the highly infectious and deadly paramyxovirus, which spread in pigeons throughout Victoria and NSW.

The disease was finally controlled and contained to pigeons, but it created a huge scare because of fears it could mutate and infect chickens.

A blue-fronted amazon (Amazona aestiva)

A similar incident involving exotic parrots was not made public.

Background Briefing has learned a smuggled exotic parrot introduced the proventricular dilatation disease (PDD) to Australia back in 2003.

PDD is a serious problem in a number of other countries but had been controlled in Australia.

"[PDD] is a huge problem in North America and through Europe, and this disease is endemic in a lot of the critically endangered parrots and a lot of the conservation programs are in place to save those birds," said veterinarian Dr Adrian Gallagher, who diagnosed six infected birds at his Brisbane clinic.

"The disease emerged in Australia in around 2003 and there was a cluster of cases around south-east Queensland and northern New South Wales."

Quarantines unenforced

When the first PDD case presented at Dr Gallagher's clinic, he says he immediately imposed quarantine conditions on the bird owner's aviaries.

However, because PDD is not officially recognised as infectious in Australia, the quarantine request could not be enforced.

Dr Gallagher says the client subsequently sold all of his bird collection before it could be determined how many were diseased.

Apart from another five unrelated cases, Dr Gallagher has not diagnosed PDD at his clinic again.

Daniel Gowland, whose family runs research and breeding facilities for parrots near Queanbeyan, says he has contacted government departments several times about his concerns about the illegal trade.

But he says his concerns fall on deaf ears.

"It would appear that there is nobody doing anything about the legal trade in animals," Mr Gowland said.

In a written statement sent to Background Briefing, Federal Environment Minister Tony Burke said his department regularly receives and assesses allegations of wildlife crime.

The statement said in some cases those tip-offs led to seizures.

The full report by Hagar Cohen can be heard on Radio National's Background Briefing on Sunday morning.