Merseyside police are to question the wife of a man who took his own life in a Switzerland clinic on Monday.

Wyn Crew is to be questioned by officers over her role in the death of her husband, Reginald, who died in a Zurich euthanasia clinic. Mr Crew was suffering from advanced motor neurone disease but under British law his wife could go to jail for up to 14 years for assisting in his suicide.

A Merseyside police spokeswoman said: "Under British law we are obliged to investigate this matter. This decision is not a moral one, but a legal one. We are putting files together and will be talking to Mrs Crew as part of our investigation. Our completed file will be passed on to the crown prosecution service and they will decide if any prosecutions are to be made."

Mr Crew, 74, died on Monday after swallowing a lethal cocktail of barbiturates in a clinic run by the non-profit euthanasia organisation Dignitas. After seeing the company feature in a television programme, the former Ford worker paid £50 to join and then chose to travel to the clinic.

Mrs Crew was present at his death and remains in the country. She is expected to return home at the weekend.

The police said anyone connected with making arrangements for Mr Crew was likely to be investigated, including the crew who were filming for a Tonight with Trevor McDonald programme that is to be broadcast this Friday.