Petrol theft is considered fraud under the NSW Crimes Act 1900, with a NSW Police spokeswoman saying officers are committed to tackling the crime.

So far during 2019/20, 38 people have failed to pay for their fuel at petrol bowsers in this police district, with legal action taken against six of them.

By comparison, in 2018/19, there were 87 fail to pay for fuel incidents reported with seven people charged.

Central West Police District Chief Inspector Peter Atkins said not all fail to pay incidents were done with criminal intent.

He said a proportion of the reported theft cases were honest mistakes and people would return to the service station to pay.

"We have a system where most [fail to pay incidents] are reported to the Police Assistance Line and it turns out that some are an honest mistake and some are fraud," Chief Insp Atkins said.

"A percentage of them are a deliberate act and they're often people in stolen cars."

Chief Insp Atkins said some motorists will use fake number plates or disguise their number plate, or they disguise their appearance during a fuel theft incident.

By comparison, in the Chifley Police District there have been 91 fuel theft cases so far this financial year, with nine people charged.

Chifley crime manager Detective Insp Rankin said unfortunately it is very "resource intensive" to investigate every fuel theft reported.

In the Orana Mid Western Police District there has been 92 fail to pay for fuel incidents at service stations, with 11 people charged.

A NSW Police spokeswoman said police are committed to tackling 'fail to pay' (FTP) crime and urged the industry to assist.

"We need the help of industry to ensure we can catch and charge those who rob services stations of fuel," she said.

"It is critical that any service station targeted by fuel thieves fill out the FTP form and submit it to police."

The Police Assistance Line operates 24 hours a day and can be reached by calling 131 444.