A sleep doctor who sliced his wife's throat open to stop her from choking may be charged with negligent manslaughter after he waited three hours to call an ambulance.

Respiratory and sleep physician Peter Spencer and his wife Mayumi, 29, had returned home to their apartment after a night out in Melbourne in January 2015 when she started vomiting and had a fit.

He tried to resuscitate her and believed she had a blockage in her throat.

Dr Spencer sliced her throat open using a kitchen knife and pen to try and open her airways, which was unsuccessful.

Despite his wife's inability to breathe, he did not call emergency services for three-and-a-half hours.

Paramedics arrived at 7.49am on January 17 and found Mrs Spencer lying on the floor of their lounge room.

Her husband was performing CPR using "pretty gentle" compressions, the coroners court was told.

She was declared dead by paramedics and her temperature taken at 33.2C, which suggested she had been dead for a considerable time.

Her medical cause of death was found to be cocaine toxicity.

Police searched the apartment and found syringes, cocaine inside a blood-stained hand vacuum and in plastic bags under clothes inside the washing machine.

Despite a thorough police investigation, no one has ever been charged over Mrs Spencer's death.

Victorian State Coroner John Cain investigated and, in findings released on Friday, recommended Dr Spencer be charged with a criminal offence.

He recommended the Director of Public Prosecutions charge him with negligent manslaughter due to the delays in seeking urgent medical assistance and Dr Spencer's duty of care to Mrs Spencer.

Dr Spencer tried to have these coronial findings suppressed from media but was unsuccessful.

Mrs Spencer was born in Sapporo, Japan and met Dr Spencer when he was visiting the country in 2006.

Over their near decade-long relationship Dr Spencer was physically, emotionally and psychologically abusive towards his wife, the court was told.

Family and friends said Mrs Spencer had told them he kicked her out of the house on several occasions, late at night, and he had punched her in the jaw, pushed her and hit her.

He sent her abusive messages calling her a "piece of s***" and on one occasion injected her with cocaine against her wishes, they told the court.

She moved out of their marital home in July 2012 and told Dr Spencer she wanted a divorce but returned to him the following month after he told her he was going to suicide.

Mrs Spencer was scared to leave her husband after this in case he tried to kill himself again and blamed her, a friend said.

In a statement to police, Dr Spencer said the couple had "fought a lot" earlier in their relationship, but it had been "really good" before she died.

He also gave the court statements from his friends claiming the couple had been happy in the 18 months before her death.

Dr Spencer has an online following in the health and wellness sector, including on Instagram where he has more than 7000 followers and goes by the name Dr.lifepro.

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