Former Sydney rugby league player Chris Dawson has broken his silence on the eve of his trial for allegedly murdering his wife Lynette, four decades ago.

The 73-year-old has left his home on the Sunshine Coast and travelled to Sydney, his fate now resting in the hands of Supreme Court Justice, Ian Harrison.

Dawson spoke exclusively to Nine News about the hearing, which could last up to eight weeks.

"I'm looking forward to justice to be served and the truth coming out. I just want the truth to come out," he said.

The couple and their two children lived at Bayview on the Northern Beaches, before Lyn vanished in January 1982.

The mother-of-two's body has never been found.

Dawson has always denied having anything to do with the suspicious disappearance but was charged with murder in 2018.

He has pleaded not guilty.