He was extradited to Sydney on Saturday morning and taken to Surry Hills police station, where he was charged.

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Robbery and serious crime squad commander, Detective Superintendent Danny Doherty, said Mr Bowie was "half-expecting" to be arrested.

"I think he had resigned himself to the fact that, one day, justice would come knocking on the door, and yesterday it came knocking at the door," he told reporters on Saturday.

"It's obviously mixed emotions for the family of Roxlyn. It's been a long journey for them.

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"The road ahead is still ongoing; we will be there for them and with them to get justice for Roxlyn."

Mr Bowie has denied his involvement in his wife's disappearance, telling A Current Affair he "didn't do it".

As he was led through Sydney Airport on Saturday, he told reporters the arrest had been a shock.

"I don't even know if she is dead or not," he said.

Superintendent Doherty acknowledged that a conviction without Mrs Bowie's body would be challenging, but said it had happened before.

"We know the road ahead is going to be challenging, but we've built a case, thanks to the community in giving us information," he said.

"It's a circumstantial case, we understand that, but we'll have our day in court and hopefully get some justice not only for Roxlyn but her family."

On Friday, Mrs Bowie's daughter, Brenda Boyd, said: "Today's news is a very bitter-sweet moment for our family.

"There isn't a day that goes by that I don't think about Mum and how kind, caring and loving she was," she said.

"There are many things I miss about her, including her shy and sweet smile. She was a devoted mother - my brother and I never doubted how loved we were. She, too, was so loved by those who were lucky to meet her.

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"I'm so thankful that police never forgot about Mum and never gave up trying to find out why she was so cruelly taken away from us."

In 2014, a NSW coroner found it was "highly likely" Mrs Bowie had met with foul play and she had died on the day she disappeared or not long after. But the manner of her death could not be established.

At the inquest, Mr Bowie spoke about his drinking and extramarital affairs.  He also admitted to forging his wife's signature on a land transfer document in 1984.

After his wife vanished, Mr Bowie told police they had argued and claimed his wife warned him that if he went to the pub, she would leave him.

Mr Bowie did go to the pub, he said, and when he got home his wife was gone, leaving behind their two children.

Earlier this year, police examined an area of land on the side of the Walgett property, locating and seizing several items they thought could be relevant to solving what happened to the missing mother.

Mr Bowie has been refused bail to appear at Parramatta Local Court on Sunday.

Anyone with information that may assist investigators is urged to contact Crime Stoppers: 1800 333 000 or nsw.crimestoppers.com.au.