NSW police have busted an alleged email scam run out of the Villawood Detention Centre.
A Nigerian man has been accused of running a multi-million dollar email scam out of a Sydney immigration centre.
The 43-year-old is among four people arrested and charged over the alleged syndicate in NSW.
Police allege he was the ringleader and that he used 16 mobile phones and 17 different sim cards to coordinate the scam from inside Villawood Detention Centre.
The syndicate was allegedly involved in a range of fraudulent activities, including romance scams, identity theft and business email compromises, defrauding Australians of more than $3 million.
Detective Superintendent Arthur Katsogiannis said investigators believe the money was sent to Nigeria.
He said it was "highly unlikely" the funds would ever be recovered.
"We can't establish at this stage who it's gone to or what it's being used (for)," he told reporters in Sydney on Friday.
"We are working with our international law enforcement colleagues to establish what's happened to that money."
The Nigerian man was charged with knowingly directing activities of a criminal group, two counts of knowingly dealing with proceeds of crime and possessing identity information to commit an indictable offence.
He is due to appear at the Bankstown Local Court later on Friday.
A 36-year-old woman, as well as a 20-year-old man and woman, were also arrested and charged with various offences.
They are all due to face Parramatta Local Court on October 2.
Det Supt Katsogiannis urged Australians to be extra careful when giving away information online, noting the emotional and psychological impact scams can have on people - as well as financial.
"People have committed suicide after losing their life savings," he said.
"It's costing taxpayers millions of dollars every year not only in Australia but worldwide and that's why it's important to identify these people."
Investigations are continuing and further arrests have not been ruled out.