The lawyer for the refugee deported back to Papua New Guinea from Fiji says corrupt immigration officials may have helped the refugee obtain a false passport.
Loghman Sawari, who was detained on Manus Island, travelled to Fiji using fake travel documents last month.
The lawyer Ben Lomai said the 21-year old refugee was being held at the Waigani police station for questioning and was yet to be charged.
He said, as a refugee, Mr Sawari should be allowed to travel.
"Loghman Sawari is already given refugee status and therefore he should be given some travel documents for him to travel," said Mr Lomai.
"It's not that Loghman is falsifying documents, no. It's people within the immigration department that falsify those documents. They wanted to do it to help Loghman Sawari."
Ben Lomai said for the police to hold his client for longer than three days without charge amounts to what's known as administrative detention.
Mr Lomai said he is monitoring the situation and is expecting a call from Loghman Sawari for assistance.