Production staff on ITV1's Tonight - fronted by Trevor McDonald - could face police questions about the assisted suicide of a Merseyside man in Switzerland.

The team, who accompanied Reginald Crew to a clinic in Zurich where he died on Monday, were making a programme about the case that will be broadcast this week.

Merseyside Police, who will also question Mr Crew's wife Win, have confirmed they are looking at all circumstances surrounding the case.

A spokesman for Granada, which makes Tonight, said it has not been contacted by police, but is happy to co-operate with any inquiry.

Sir Trevor McDonald presents the Tonight programme

Mr Crew, 74, from Hunts Cross, Liverpool took a lethal does of barbiturates at an apartment run by the Dignitas organisation.

He was terminally ill with motor neurone disease, which he had been suffering from for four years.

A Granada spokesperson said the crew were there as passive observers, and all decisions and arrangements were matters entirely for Mr Crew and his family, which the team took no part in.

Swiss law does not state that assisted suicide is legal but the practice is widely considered as a "humane act".

Prosecution is extremely unlikely unless the person helping is proven to be acting out of self-seeking motives.