Two men shot dead in quiet Cambridgeshire villages were father and son, police have confirmed, adding that one line of inquiry is that the attacks followed a family dispute over a custody battle.

Police officers were called to properties in Meridian Close, Bluntisham, and then The Row, Sutton, last night (Wednesday March 29) with reports of gunshots.

Officers said the bodies of the men - aged 32 and 57 - had gunshot wounds and that both deaths were being treated as murder.

READ MORE: Follow our live blog on Bluntisham and Sutton shootings 

Three people - a 27-year-old man, 66-year-old man and 33-year-old woman - have since been arrested on suspicion of conspiracy to murder. 

A car that was believed to have been used by the offender, a white Peugeot 208, and a shotgun have been recovered.

A Cambridgeshire Constabulary spokesperson said: "We have confirmed the victims are father and son.

"One line of inquiry is that it was a family dispute over a custody battle."

READ MORE: Floral tributes left after fatal shootings of two men in Cambs villages

READ MORE: Crime Commissioner issues statement on Bluntisham and Sutton shootings

Speaking to ITV News at lunchtime, Cambridgeshire Police chief superintendent Jon Hutchinson said it quickly became apparent to police that the two cases were related.

"We are working on the basis that those two individuals are father and son. 

"Having identified that, it became quite apparent this was a very targeted and isolated attack. 

"But it also gave us a chance to work out a potential motive.

"Having identified what that was, it allowed officers to move very quickly and make arrests."

READ MORE: Three arrests after two men shot dead in Cambridgeshire villages

Anyone with information should report online here or via the web chat service and quote Operation Scan.

Those without internet access should call 101.