Media playback is unsupported on your device Media caption Michael Hayes said he was speaking out to give 'the point of view of a participant'

Police have asked the BBC to provide a copy of an interview with a self-confessed IRA bomb-maker who said he was part of the group responsible for the Birmingham pub bombings.

Twenty-one people were killed on 21 November 1974 when two bombs exploded in bars in the city's centre.

Michael Hayes told the BBC last week that he took "collective responsibility" for the IRA's actions.

West Midlands Police has written to the BBC to request the full interview.

Media playback is unsupported on your device Media caption The Birmingham pub bombings explained

The force's Chief Constable Dave Thompson told a meeting of the West Midlands Policing and Crime Board on Tuesday that comments by Hayes screened in a BBC documentary had been "carefully reviewed".

"Our approach is where new facts come to light they are scrutinised to see if people can be brought to justice," Mr Thompson said.

"We have written to the BBC requesting the full footage to enable us to assess the full interview as part of our evidential process.

"Michael Hayes is outside the UK and a decision on what additional action can be taken will be assessed by the Crown Prosecution Service."

Media playback is unsupported on your device Media caption Families of the victims expressed their anger at Hayes's apology

Mr Thompson added that while the police inquiry is not active it has not been closed and the victims' families will be kept informed.

The BBC said it had received the police request for the interview and "will consider it in accordance with our editorial guidance and policies for requests of this nature".

'Gutless and spineless'

No-one has been brought to justice for the double attack, which was one of the worst single losses of life during the Troubles.

Six men - known as the Birmingham Six - were wrongfully convicted of the murders and spent 17 years in jail before they were released in 1991 when their convictions were quashed.

In last week's interview with BBC News NI reporter Kevin Magee, Hayes said he had been in the IRA for more than 30 years and was "a participant in the IRA's activities in Birmingham".

Image caption Twenty-one people died in two explosions in Birmingham bar in November 1974

The 69-year-old, who lives in Dublin in the Republic of Ireland, said two people planted the bombs in the Mulberry Bush and the Tavern In The Town, although he refused to say who they were.

He also issued an apology to the families of the victims, adding: "My heartfelt sympathy to all of you for a terrible tragic loss that you have been put through."

That was rejected by one woman whose 18-year-old sister was killed in the attack.

Julie Hambleton described the former IRA man as "gutless and spineless" and said his apology was offensive.

Media playback is unsupported on your device Media caption Michael Hayes said he apologised on behalf of 'all active republicans' for the bombings

Hayes said he was speaking out to give "the point of view of a participant".

When asked if he had planted the gelignite explosives, he replied: "I'm not telling you."

Hayes said he had been arrested and questioned in 1974 by West Midlands Police about the Birmingham bombings, but was released.

Birmingham MPs have called for Hayes to be extradited and face questioning by police.

Inquests into the deaths of the 21 victims are due to resume later this year.