Heroin disguised as copy paper-police bust

Drug smugglers tried to disguise kilos of heroin as "copy paper" in a shipment of children's clothing from Asia.

But police uncovered the scam after X-raying the consignment that arrived in Sydney from Thailand on May 1.

Tests on the paper were positive for heroin totalling 16kg, with a potential street value of $8 million.

The joint operation by NSW Police and Australian Border Force later led to the arrest of a man, 45, in Cabramatta, in Sydney's west.

"We know we have put a decent dent in availability on the street but we can't stop there," NSW Police Drug and Firearms Squad Detective Chief Inspector Jason Weinstein said on Friday.

"We will continue our inquiries into where it came from and where it was going."

Further arrests are expected.

The man was charged with commercial drug supply and refused bail ahead of a court appearance in July.