Documents obtained by the ABC warn that the Therapeutic Goods Administration (TGA) is proposing to cut senior staff at a time of increasing criminal activity in the importation and sale of counterfeit medicines.

Key points: TGA wants to cut number of senior investigators in Regulatory Compliance Unit from five to three

TGA wants to cut number of senior investigators in Regulatory Compliance Unit from five to three Documents say bikie gangs, terrorist fundraisers flooding market with counterfeit Viagra, weight loss pills

Documents say bikie gangs, terrorist fundraisers flooding market with counterfeit Viagra, weight loss pills AMA says TGA's staffing changes would be a backwards step

The TGA, the body regulating the sale and importation of medicines, is proposing to cut the number of senior investigators who liaise with police, Customs and Border Force agencies, in favour of more junior staff who can write warning letters over alleged breaches of the TGA's Act.

At the same time, a leaked internal document says the TGA is dealing with an "an upward and emerging trend with more counterfeit medicines and unregistered medicine matters with entities responsible displaying criminality and/or non-compliance".

The documents say outlaw motorcycle gangs and terrorist fundraisers have recognised the financial gains available from the importation and sale of counterfeit erectile dysfunction and weight loss medicines.

Health experts warn these drugs pose a serious danger to public health.

Monash University Associate Professor Ken Harvey said there was a cocktail of dangerous drugs being mixed with counterfeit Viagra available online.

"This is crazy stuff. Not only has [one] got Viagra in it, it's got chloramphenicol, which is a quite powerful and dangerous antibiotic," he said.

"It's a last-ditch antibiotic which can cause aplastic anaemia and can knock out your bone marrow."

The Australian Medical Association's Tony Bartone described the proposed changes at the TGA as a backwards step.

"Anything that would see a reduction in powers of the TGA in ensuring that the community can have confidence in the medicines that they take every day would be a significant backward step in my view," Dr Bartone said.

An external review prepared for the TGA looks at the role of senior investigators in the Regulatory Compliance Unit.

It outlines a case where investigators identified an individual connected to an outlaw motorcycle gang importing counterfeit erectile dysfunction pills to sell online.

The investigators alerted police to the case.

Union says TGA already understaffed

The Regulatory Compliance Unit has seven senior investigators who liaise with police forces, Customs and Border Force over the importation of counterfeit medicines and dodgy health products.

The restructure proposes to reduce the number of senior investigators to three.

Community and Public Sector Union spokeswoman Beth Vincent-Pietsch said the TGA was already understaffed.

"The compliance unit of TGA is woefully understaffed and it is unable to meet its obligations in order to ensure that the Australian public are safe," she said.

"The unit used to have 17 staff, it's gone to five and now they're looking at dumbing down the service even more."

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 3 minutes 48 seconds 3 m 48 s Cuts at TGA as police say counterfeit drugs are on the rise

A TGA spokeswoman said a review of its regulatory compliance section made 16 specific recommendations regarding its areas of work including its intelligence function and intra-agency collaboration and communication.

The TGA said it was working to implement the restructure by May this year.

In a statement it said the changes would actually increase the number of officers.

"The implementation of the review will not impact our ability to ensure compliance with the TGA regulatory scheme and our ability to prosecute offenders where prosecution is warranted," it said.