0352 GMT January 28, 2020
Chris Dawson, 70, is to be charged with murdering Lynette Dawson, New South Wales (NSW) authorities said, BBC wrote.
Mr. Dawson has denied killing Mrs. Dawson, with whom he has two children. He has said that she abandoned the family for a religious group.
A podcast, ‘The Teacher's Pet’, brought global attention to the case this year.
Police arrested Mr. Dawson in Queensland and said he would be extradited to NSW.
Mrs. Dawson's brother, Greg Simms, said he was "ecstatic" about the development.
"We've always been determined to find the truth and that's the reason why we've fought to keep Lyn's name alive," he told Nine News.
Two separate inquests have recommended for murder charges to be laid against a "known person."
However, prosecutors have previously said there was insufficient evidence to lay charges. No trace of Mrs. Dawson has ever been found.
A search of the family's former home in Sydney earlier this year failed to turn up new evidence.
However, police said the arrest followed three years of renewed investigations.
"We are confident with the case," Supt. Scott Cook told reporters on Wednesday.
"We won't give up on trying to identify the whereabouts of Lynette Dawson, but, from our perspective, it is not crucial to finalizing the matter."
An inquest in 2003 found that Mr. Dawson, a former high school teacher and rugby league star, had engaged in unethical relationships with teenage students during his marriage.
One 16-year-old girl moved in to the family home within days of Mrs. Dawson's disappearance. The pair later married, but have since separated.
Since May, more than 27 million people have listened to ‘The Teacher's Pet’ podcast, which is produced by The Australian newspaper.
It has highlighted the bungled handling of Mrs. Dawson's case by police in the early years after her disappearance, prompting a recent apology from the state's police commissioner.