TV presenter Ray Gosling has been arrested on suspicion of murder by Nottinghamshire Police after he admitted killing his lover.
The 70-year-old's confession that he had smothered the unnamed man who was dying of Aids was broadcast on the BBC's Inside Out programme on Monday.
The Nottingham filmmaker said he had made a pact with his lover to act if his suffering increased.
Police are questioning the presenter over his claims.
A police spokesman said: "A 70-year-old Nottingham man was arrested earlier on suspicion of murder following comments made on the BBC's Inside Out programme on Monday evening."
Mr Gosling has previously said he would not name his lover or say when the incident took place.
In the BBC East Midlands programme, broadcast on Monday, he told how he smothered the man with a pillow while he was in hospital after doctors told him that there was nothing further that could be done for him.
Mr Gosling did not name either his lover or the hospital.
Ray Gosling's solicitor, Digby Johnson, spoke outside Oxclose Lane Police station earlier.
'Very difficult times'
He said: "Ray has been at the police station for approaching five hours and investigations are at a very early stage.
"He's in good spirits but these are very difficult times for Ray.
"Everybody has been carefully respecting Ray's wishes and I request that you do the same."
Mr Gosling said he was aware of the possible consequences and had no regrets.
In the film, he said: "It's a terrible situation. I loved him to bits.
"We had a pact - he said if the pain gets bad and if nothing can be done, don't let him linger on.
"I don't think it's a crime."
He said: "I said to the doctor: 'Leave me just for a bit,' and he went away.
"I picked up the pillow and smothered him until he was dead.
"The doctor came back and I said: 'He's gone.' Nothing more was ever said.
"When you love someone, it is difficult to see them suffer."
Assisted suicide remains a criminal offence, but interim guidelines issued in September by the director of public prosecutions set out the factors which weigh in favour of and against prosecution.