They All Died Laughing 1964

Synopsis:

An English professor decides that there are too many useless people in the world and invents a gas that will kill them off. But first they'll at least have a good laugh.

Directed by: Don Chaffey
Written by: Robert Hamer & Donald Taylor
Runtime: 94 minutes
Tagline: THEY ALL DIED LAUGHING
Cast:
Leo McKern
Leo McKern
Professor Kerris Bowles-Ottery 
Janet Munro
Janet Munro
Delia Brooks 
Maxine Audley
Maxine Audley
Clarinda Bowles-Ottery 
Dennis Price
Dennis Price
Dr. John Hughes 
Miles Malleson
Miles Malleson
Dr. Woolley 
Mervyn Johns
Mervyn Johns
Willie Pugh-Smith