Scammers have fleeced migrants of more than $6000 after pretending to be government officials.
The scammers, who claim to be from the foreign affairs or immigration departments, call potential targets - especially migrants from India - accusing them of giving false information on visa or departure documents on their return to Australia.
They're then told to hand themselves into police, pay almost $1000 or face deportation.
The scam looks legitimate because the number which appears on the phones of targets is in fact the DFAT number.
The Scamwatch received more than 20 reports in May.
The Australian Competition and Consumer Commission says anyone receiving a phone call out of the blue from someone claiming to be from the two departments or any government agency telling you that you have done something wrong or threatening you and asking for money, hang up.
"If you have any doubts about someone who says they are from a government department, contact the department directly," " deputy chair Delia Rickard said in a statement on Wednesday.
