Thirty-four Malaysians have ended up in an Australian immigration detention centre after falling victim to fruit picking scams.

The issue was highlighted by Bersih Sydney, which said it was approached by Salvation Army Australia to help the Malaysians, including two minors, who are now detained at the Villawood Immigration Detention Centre.

In a Facebook posting, Bersih Sydney said the Malaysians were detained for deportation after being caught working as fruit pickers on a blueberry farm in Coffs Coast without valid visas.

"It was soon clear that these illegal workers had fallen victim to a scam that is becoming increasingly prevalent," it said.

It said agents operating in Malaysia, some linked to tour companies, claim they can help Malaysians to obtain fruit-picking jobs in Australia from as low as RM3,999 which covers air fare, hotel expenses, visa application, accommodation and transportation.

It said the agents mislead interested Malaysians that tourist visas, bridging visas or even student visas are sufficient to allow them to work in Australia.

"This usually leads to them working on fruit farms beyond the stipulated work hour limit, exposing them to having their visas revoked.

"Once these workers are caught, the 'agents' would refuse to get involved, while the victims would bear the consequences and risk being deported," it said.

Furthermore, those working on the farm are also subjected to poor working and living conditions, and receive below the minimum wage.

"Currently, our team members, together with the Australian Salvation Army, are working with authorities seeking to bring this crime to an end.

"We strongly advise everyone to stay informed on such scams and to only obtain Australian visas through reputable channels," it said.

The Australian High Commission in Malaysia also issued a statement warning against such scams.

"We are aware of facilitators in Malaysia organising visas and flights to Australia for people who intend to work illegally on their Electronic Travel Authority (ETA) visa.

"This is a scam attempting to intentionally mislead people, often for money or other personal gain. An ETA does not permit you to undertake paid work (such as fruit picking) in Australia. Don't be fooled by these scams.

"If you work in Australia in breach of your visa conditions, you may be detained and removed, and subject to the three year exclusion period.

"It is your responsibility to know what your visa allows you to do while in Australia," it said.