Married couple William Cowell and Joan Taylor went missing 30 years ago. It's believed they were going fruit picking in the Gympie or Wide Bay area.

Married couple William Cowell and Joan Taylor went missing 30 years ago. It's believed they were going fruit picking in the Gympie or Wide Bay area. Contributed

POLICE do not believe the couple missing for 30 years are alive but nor do they think they met with foul play.

Detective Senior Constable Mike Fernald said the family of William Cowell and Joan Taylor had never stopped searching for them.

The couple were last seen in 1983 when they were believed to be going fruit picking in the Gympie-Wide Bay region.

"They were in very poor health, they were very frail, th last time they were seen they were in their 60s venturing out to an unknown farm to pick fruit," he said.

"However, in the state they were in, it would've been an odd time to be going somewhere to do manual labour.

"It was right around that the time their son Alan drowned and daughter Christine was diagnosed with cancer - so it's just timing, we don't think it's foul play.

"We don't believe that they are alive."

Snr Const Fernald said there were a lot of mental health issues with the family and the couple "learned of Alan's drowning and Christine's terminal cancer and drove off into the sunset".

"Just to assist the family, police now are seeking assistance from the general public, to assist the family in getting some closure," he said.

Snr Const Fernald said the couple were reported missing in 1984 and the procedure at the time was to let the Salvation Army missing persons program deal with it.

The Salvation Army ran an extensive television and print media campaign in mid-1985, he said.

The family engaged independent solicitors and spent quite a bit of money funding a search, all with negative results.

The search has been going on for 30 years and it's quite profound

"They've never stopped looking, the search has been going on for 30 years and it's quite profound. It's gone from generation to generation, so the family are to be commended actually, they never stopped searching," Snr Const Fernald.

"Each person would conduct their inquiries and as people would pass on, then new family members would continue the search.

"We're almost 30 years down the line.

"We have Melissa (Bishop), who is the granddaughter of the missing persons. She is now carrying the torch and she is continuing the search."

He said not a single trace had been found of the couple during the three decades they had been missing, which was why police were appealing to the public.

"William and Joan were free spirits," Snr Const Fernald said.

"They lived for the moment, they were good people, very quiet, kept to themselves and they would often go on fruit-picking journeys.

"They would pack up the car and just venture out and get employment on different farms picking fruit.

"It was during one of those trips when they went missing.

"We've used massive resources on this.

"We've exhausted those avenues of inquiry.

"There might be somebody out there who may have known William or Joan or may have known of them spending time in Gympie or the Gympie region.

"We're just hoping that somebody out there can shed some light on the mystery."

He said no members of the public had contacted police with useful information over the years.

Snr Const Fernald asked anyone with knowlege of William or Joan to come forward to help solve the mystery.