Voluntary euthanasia advocate Dr Philip Nitschke will not provide advice on suicide and euthanasia, after agreeing to conditions imposed by the Medical Board of Australia.

The Medical Board is set to announce the 25 conditions Dr Nitschke has reportedly agreed to, following the board’s long investigation into his work.

The most significant condition will see him stop endorsing or encouraging the suicide of any member of the public.

Dr Nitschke has also agreed not to practise medicine in the Northern Territory.

The deal comes more than a year after he was suspended for admitting in an ABC interview that he supported 45-year-old Perth man Nigel Brayley's decision to take his own life.

Mr Brayley allegedly admitted to Dr Nitschke that he was not “supporting a terminal medical illness”, but did say he was “suffering”.

The high-profile doctor and euthanasia advocate will stop hosting workshops on euthanasia methods, as well as cease providing advice and testing kits for euthanasia drugs.

Dr Nitschke is not even allowed to speak publicly about the agreement with the Medical Board, according to his wife Dr Fiona Stewart.

She said it was an unreasonable restriction.

“He won't be allowed to talk about assisted suicide, or euthanasia or any member of the public,” Dr Stewart said.

“It kind of sounds the death of free speech in Australia.”