The mother-of-two mysteriously vanished from her family home in the Northern NSW country town of Walgett, in June 1982.
In 2014 a coronial inquest into the disappearance ruled that Bowie had died, but the cause of death could not be determined because her body has never been found.
Ms. Bowie was 31 at the time of her disappearance and was last seen leaving her home at 6 pm on Saturday, June 5.
Six days after his wife’s disappearance, John Bowie applied for a transfer to Sydney. He was sent to Bankstown where he met a woman, whom he married the following year.
According to ABC News, Dozens of police have now gone to a massive dam as well as an industrial site on the outskirts of Walgett, after receiving a tip-off.
The site covers a large area, and police say the search could take a couple of weeks.
Detective Superintendent Daniel Doherty believes that there are people who have important information surrounding the suspected murder of Roxlyn Bowie, but they are either afraid or hesitant to come forward to police.
The case was just recently re-opened by investigators, and earlier this month a $1 million reward was offered by the NSW government for anyone who can provide information about the missing woman.
Brenda Boyd, Roxlyn’s daughter, has made a public plea for help, “It’s been 36 long years without having my mother there for birthdays, holidays and special milestones,” Ms. Boyd, who was six years old when her mother disappeared continued,
“It’s not fair that we’ve gone most of our lives without knowing why she was taken from us. I urge people to put themselves in my position and realise just how important it is that we find the truth.”
Roxlyn Bowie’s husband, now 68-years-old, has denied any involvement in her disappearance.