Glamour model Mark Johnston's murder leaves his French lover in the dark

Mark Johnston, model and gambler, disappeared in September 1986 from Dover Heights. Photo / News Corp Australia

He was the well-off globetrotting playboy, a face of Coca Cola commercials and a fashion model with much to live for, not least of all his beautiful French girlfriend Simone-Maree.

But Mark Johnston's lifestyle also brought him into contact with Australia's criminal underbelly and that would end their dreams and his life.

Such was the mystery surrounding his disappearance and presumed death tragically 30 years ago it was likely Simone-Maree never knew what happened to her lover from the other side of the world and possibly led her to believe he simply ran out on her, reports news.com.au.

"The woman was waiting for him, I felt really bad because none of us knew her, Simone Maree was her name but we had no details," Johnston's sister Diana Devitt-Dawson recalled yesterday.

"I was always thinking that maybe the poor woman never knew what happened, no-one ever told her. We could never make contact with her, we didn't have any details … he was supposed to be flying back to her in France after coming back to Australia to collect the money but he was never seen again."

It was August 1986 when Johnston disappeared, an age before mobile phone and the internet and instant connections.

Mark Johnston, model and gambler, disappeared September 1986 from Dover Heights. Photo / News Corp Australia

The Queenslander met Simone-Maree in the up-market seaside town of Biarritz in the south west of France and the pair decided to make their life there. They had seen a block of land they thought they would build on and Johnston told his girlfriend he would return to Australia for a brief trip to collect $60,000 he had left in safekeeping with his solicitor, to help make that dream happen.

He flew back to Sydney and was actually at his own farewell party in Paddington in inner Sydney when he told friends he would just step out to collect his money and come back to the party. He was never seen again. His Holden Commodore rental car was found in Matraville with a case of cocaine and some cash.

Every 18 months to two years NSW Police conduct a search for his body close to the ever-shifting estuaries and beach sand dunes about Sydney Airport's third runway. That search is to take place in coming weeks with the cold case again up for review.