Qld women planned their deaths: Nitschke

A euthanasia advocacy group has confirmed a Gold Coast mother and her two daughters had spent months planning their deaths.

The bodies of Margaret, Heather and Wynette Cummins were found in one of their homes following an apparent triple suicide pact on Tuesday.

Euthanasia advocate Dr Philip Nitschke said he did not personally know the women but confirmed they had joined his Exit International group six months ago.

"They were not terminally ill people but on the other hand, they were not in the best of health either," he said, speaking from Amsterdam on Wednesday.

"They were obviously working out what they wanted to do."

A Gold Coast man returned to the luxury residential estate of Ephraim Island at Paradise Point on Tuesday to find his wife, mother-in-law and sister-in-law dead.

It's believed all three had medical problems and their deaths are being treated by police as non-suspicious.

They have been mourned by neighbours in the upmarket residential community.

Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14.

Suicide Call Back Service 1300 659 467.