Victoria cops assisting in Mackay case

Police are chasing fresh leads in the 1977 assassination and disappearance of anti-drug campaigner and Liberal Party candidate Donald Mackay.

Detectives from Griffith Local Area Command have been sent to Victoria, a spokesman for NSW police told AAP on Wednesday.

"They are examining possible links between Donald Mackay's death with Victorian crime figures," the spokesman said.

"I can confirm they are working with our Victorian colleagues."

Mr Mackay disappeared from a car park in Griffith on June 15, 1977.

Police found hair, bloodstains, spent bullet cartridges and drag marks at the scene - but not Mr Mackay's body.

Authorities dug up farmland in western NSW last year but failed to find any trace of Mr Mackay's body.