Missing woman's double life 'was a secret'

The brother of a New Zealand nurse who disappeared from Sydney in 1980 had no idea about his sister's secret life as a prostitute and heroin addict.

Marion Sandford wrote a letter to her brother, Peter Sandford, in January 1980 saying she had gone to meet friends and would be back at the suburban Cammeray home they shared within a week.

"I am not at all sure when I will be home but it should be within two days to one week at the latest I suppose! Met a couple of friends. See you later, love Marion," she wrote in a letter posted from Sydney's Central Railway Station and post-marked January 29, 1980.

But the 23-year-old vanished without a trace.

Mr Sandford, who lived in Melbourne and Sydney in the 1970s, said his sister was the highest achieving of the four siblings.

However, she had been troubled when she became a nurse and subsequently left New Zealand to join him in Sydney and sort out her drug problems.

Mr Sandford, who said he was often away for work at the time, had believed his sister's drug use was recreational.

"I didn't have an inkling of the depths of Marion's addiction," Mr Sandford told the Glebe Coroner's Court inquest into her presumed death.

"I found out about the prostitution after Marion was missing."

Asked by counsel assisting the coroner Sophia Beckett what he thought Marion and her boyfriend Warren Mills were doing out every night, Mr Sandford said he had naively believed anything his sister told him.

"She explained to me that Mr Mills' mother was ill," he said.

"I thought they were going and visiting her."

The siblings flew to Auckland for Christmas in December 1979, and Ms Sandford pledged to sort out her drug problems, pay back her debts to family and attend to court matters in Sydney.

"She said in Christmas that she definitely wanted to change her life," Mr Sandford said.

Angela Sandford said her sister seemed unsettled on her last visit to New Zealand and was reluctant to go back to Australia.

"If Marion was still alive I definitely would have heard from her," said a weeping Ms Sandford.

Warren Mills, whom she dated from 1978, also gave evidence on Tuesday.

Mr Mills said Ms Sandford was approached by their North Shore drug dealer David Pierce to do a drug run to Malaysia.

"She was quite keen (to go)," Mr Mills said.

"It was money and cheap drugs."

However, Mr Mills said a drug run to Malaysia took two to three weeks and he didn't believe Ms Sandford had ever got a passport.

He said Ms Sandford's addiction went from using heroin once a fortnight to four times a day towards the time she disappeared.

He said she became a prostitute and worked the streets of Kings Cross to support the pair's $200 to $300 daily habit.

"I used to just like hang around, stay in the car, and try and follow her when she got into a car," Mr Mills told the court.

On one occasion, he had lost her when she was picked up by two men who forced her to take LSD and raped her, he said.

Coroner Paul MacMahon will deliver his findings on Wednesday morning.