Blenheim 1 mid-air collision summer 1940

[Colin Osborne]

Can any one please cast any light on an incident my father saw when he was working in the harvest fields during summer 1940. Just south of Cambridge, over Trumpington, my father watched 2 Blenheim 1s in a mock dogfight which resulted in a collision between the two aircraft. One lost a wing and the other lost its tail. Both were seen to spin to the ground with no parachutes emerging. My father did not want to go to see the wreckage but apparently some older boys went and confirmed the crew were still in the aircraft.
Any info please?

Colin.