Accused Wife Killer John Bowie Refused Bail, In Jail Until December

A man accused of murdering his wife more than 37 years ago in northern NSW will remain behind bars until at least December.

Almost four decades after his wife Roxlyn disappeared, John Bowie on Sunday faced Parramatta Bail Court charged with her murder.

The 69-year-old denies killing Roxlyn, who vanished from her Walgett home on June 5, 1982. Her body has never been found.

Bowie did not apply for bail at court on Sunday and it was formally refused.

He's scheduled to next appear before Central Local Court on December 2.

"I don't even know if she's dead or not," Bowie told reporters on Saturday as detectives escorted him through Sydney Airport en route to Surry Hills Police Station.

He had been arrested at Queensland's Woodford Correctional Centre on Friday and extradited to NSW.

A coroner in 2014 found Roxlyn was dead but couldn't determine the cause of death.

Police admit the circumstantial case will be challenging to prove without Ms Bowie's body.

"It's happened before, we know the road ahead will be challenging," Detective Superintendent Danny Doherty told reporters on Saturday.

New interviews with witnesses and technical advances in uncovering forensic evidence helped progress the case.

Two separate searches in Walgett in the past year revealed personal items, including a silver ring with the letter "R" and black and gold packaging for a Swann-Morton surgical blade.