Three firefighting utes have been seized among 26 cars, boats and trailers in an alleged rebirthing scam worth over $1.25 million.

The NSW Rural Fire Service utes - worth an estimated $290,000 - vanished while being fitted-out for the fire front.

Five men from Western Sydney have this month been arrested and charged over the alleged rort.

The syndicate allegedly worked by replacing the unique identity numbers on the stolen vehicles and boats with numbers from legitimately registered vehicles.

The stolen vehicles and boats were allegedly due to be on-sold or kept by syndicate members.

The Financial Crimes Squad's Motor Unit came across the alleged syndicate when they began investigating reports of fraudulent green slips in November.

"They were stealing the motor vehicles then someone in the organisation would assist in removing the identifiers and re-identifying the vehicles," Detective Chief Inspector Con Galea claimed.

Strike Force Piddington detectives have swooped on the syndicate over the past fortnight, first arresting a 25-year-old man in a vehicle stop at Ermington.

He was charged with knowingly facilitating organised car rebirthing, participating in a criminal group contributing to criminal activity and six counts of knowingly dealing with proceeds of crime.

Four other men - aged between 26 and 32 - were later arrested at Condell Park, Ermington and Seven Hills and charged with various related offences.

The seized vehicles included Toyota HiLux and Landcruiser utes as well as six fishing boats on trailers.

Chief Insp Galea said the three RFS utes were stolen while they were having work done in Yennora.

"These are emergency service vehicles, that are essential resources for the organisation and the community - particularly after what the state endured last summer," he said.

Chief Insp Galea said a number of the vehicles were not insured by their original owners, causing "significant financial hardship".

He said that generally speaking, rebirthed vehicles were a major safety threat to unwitting buyers because major alterations were made to the vehicles. He added there was also a risk the RMS would refuse to register a car once it was reveal

Originally published as Syndicate targets RFS utes in $1.25m alleged rebirth 'scam'