One of Chris Dawson's relatives went missing in eerily similar circumstances to his wife Lynette, his lawyer has revealed.
Dawson's brother Peter's mother-in-law vanished without a trace in the 1960s, leaving behind a husband and three children.
The woman - named Marcia - was found to have fled to New Zealand and remarried, before dying in 2002.
Dawson's lawyer Greg Walsh spoke about the strangely similar case, making a point that sometimes people do just disappear.
Peter Dawson said he believes Lynette Dawson may have also fled to New Zealand, The Daily Telegraph reports.
'We don’t know where Lyn is. I hope she is living happily somewhere in the world,' he said.
The bizarre coincidence comes as Dawson is charged with the homicide of his former wife Lynette.
Mr Walsh confirmed Dawson is pleading not guilty to the charges and will be 'strenuously' protesting his innocence.
Lynette disappeared from her Northern Beaches home in January 1982 and has been missing presumed dead ever since.
Dawson's extra-martial affair with schoolgirl Joanne Curtis and the suspicious circumstances of Lynette's disappearance has been the subject of critically acclaimed podcast The Teacher's Pet.