Voluntary euthanasia advocate Philip Nitschke will be interviewed by South Australian police today as part of an investigation into the death of a terminally ill man who took his own life.

Max Bromson, a local Senate candidate for the Voluntary Euthanasia Party, died in an Adelaide motel room on Sunday night after taking a lethal drug in the presence of his family.

The 66-year-old had been suffering from bone cancer for five years, and bought Chinese Nembutal after joining the Exit International “buyer’s club”.

The Nembutal used by Mr Bromson was tested for its purity at Dr Nitschke’s Adelaide clinic.

South Australia Police says its Major Crime Unit is investigating to see if the criminal offence of assisting in a suicide has been committed.

“My legal advice now is to just leave the decision now about whether my involvement with the exact details of Max’s death to be determined by them, in so far as whether or not they believe any breach of the law has been committed,” he said.

Dr Nitschke’s registration was suspended last week over his involvement with a Perth man who took his own life but was not terminally ill.

Dr Nitschke, who was a friend of Mr Bromson, says he has been heartened by support from the Bromson family.

Kerry Bromson, Mr Bromson’s sister, says she and other family members were present when he took his life.

She says they have since been questioned by police.

“We fully understand their stance on it and why they have to do that. We don’t have any objection to that because, in principle, we never assisted our brother,” she said.

“We had this organised, he did it himself, he drank the product himself. We were there just of support to him and to show him our love.”

Mr Bromson left a note and filmed his own death to prove his family did not assist him.

His son Matthew, a Broken Hill businessman, says he hopes his father’s death prompts a meaningful discussion about changing laws on euthanasia.

“Max has always been super open about it and spoken to everyone about it,” he said.

“If people are supportive that’s fantastic, but I guess Max has made the ultimate statement.”