An investigation into the shooting of a taxi driver in Sydney's west more than 50 years ago will be reviewed by NSW police amid claims it may have been committed by serial killer Ivan Milat.

Milat's older brother, Boris Milat, told Channel 7's Sunday Night program that the notorious backpacker killer admitted to shooting taxi driver Neville Knight from the back seat of a cab at Smithfield in March 1962.

The bullet lodged in Mr Knight's spine, paralysing him for life. Boris said Milat told him about the crime the next day but he kept it a secret for five decades to protect his younger brother - who was 17-years-old at the time.

A police spokesman on Monday said police would examine the information broadcast by the program on Sunday.

"We can confirm police are reviewing the information presenting in last night's TV programme," a police spokeswoman said.

Another man, Alan Dillon, was jailed for five years for the crime. Mr Dillon told Sunday Night he only confessed to protect his younger brother, who he thought was behind the attack.

If it was Milat, it would have been his first known violent crime - occurring decades before he murdered seven backpackers in the Belanglo State Forest south of Sydney.

Boris Milat, who changed his name to Steven Miller after his last name became notorious,  said his brother told him the gun went off with a "hair trigger" and the driver cried out "you've ruined me" four or five times.

"[Ivan] told me so. He told me the day after it happened," Mr Miller told Channel Seven. He said he did not go to the police because his "thinking didn't go like that [back] then".

"I was too much of a Milat," he said.

Mr Miller described a younger Milat as "sneaky" and "sadistic", describing how his younger brother would pop out of long grass to surprise people near their childhood home and had attacked animals with machetes.

The former detective who led the investigation into the backpacker murders, Superintendent Clive Small, said the claim by Mr Miller appeared "sincere".

Though he did not directly connect the shooting to Milat's future crimes, he said any crime would have added to a pattern of confidence and control that exhibited itself in the backpacker murders.