The Ringer

I know memories at my age (84) can play annoying tricks on you but I definitely remember seeing Alexander Knox in a film of the above name.The story line was about somebody who 'squeaked' on his friends and was under protection by the police, the character played by Alexander Knox, was the one to seek revenge. I vaguely remember that the Squeaker was played by an actor whose surname was Lawson. A black and white film with sound track. The final words in the film came from Alexander Knox as he made his get-away in a two-seater plane with his girl-friend in the rear cockpit was---'Do you love me, Cora-Ann'. Can anybody help?