"A 70-year-old Coolum man was arrested by detectives from the Queensland Police Service's Homicide Squad in the presence of Strike Force Scriven investigators at Biggera Waters, on the Gold Coast, in Queensland", NSW police said.
Queensland Police said Mr Dawson's extradition to NSW was unlikely to take place on Wednesday because of continuing negotiations with the commercial airlines over security arrangements.
The case has risen to recent prominence as the subject of record-breaking podcast The Teacher's Pet.
The husband of Sydney mother Lynette Dawson, who disappeared nearly 40 years ago, has been charged with her murder.
Just a few days later, he moved his schoolgirl lover into the family home.
Comm. Fuller said two additional witness statements had been taken since April, but would not comment on the significance of that evidence.
Commissioner Fuller says they won't give up on trying to identify Lyn's whereabouts but locating her remains isn't crucial to finalising the matter.
It was revealed that Chris Dawson went "quietly" with police following his arrest this morning, and that no new evidence was found during the September dig at the Bayview property.
He was refused bail to appear at Central Local Court on Thursday afternoon.
"A team of dedicated detectives has been investigating this case over the past three years", he said in a statement.More news: Alabama's Tua Tagovailoa facing ankle surgery
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Mr Dawson's family released a statement yesterday, insisting he would be found not guilty.
He'll be charged with murder later today.
Police allege Mr Dawson was in the process of divorce from his wife and he was having an "illicit affair".
But he said the case could be run successfully without finding her body.
"We have solved homicides before without identifying the body", Comm.
It comes after detectives from the Homicide Squad's Unsolved Homicide Unit established Strike Force Scriven in 2015 to re-investigate the circumstances surrounding Lynette's disappearance and suspected murder.
Just weeks before her daughter was due to start kindergarten, Mrs Dawson disappeared and has not been seen or heard from since.
"I'm the happiest man alive today, and if Lynette is up there looking down, she'd be smiling at us", he told News Corp Australia.
But his arrest yesterday on the Gold Coast was a sudden development of case that has never been far from the headlines during the 37 years that have passed since Lyn's disappearance.
However, prosecutors have previously said there was insufficient evidence to lay charges.