Let's Kill Uncle 1966

Synopsis:

A 12-year-old orphan who has just inherited a fortune is trapped on an island with his uncle, a former British intelligence commander who intends to kill him. A young girl is the boy's only ally against the sarcastic uncle, who uses hypnotism, a pool of sharks, fire, and poisonous mushrooms as weapons.

Directed by: William Castle
Written by: Mark Rodgers
Runtime: 92 minutes
Tagline: LOVABLE OR LETHAL? Are they bad seeds...or frightened innocents caught in a diabolical duel with death!
Cast:
Nigel Green
Nigel Green
Major Kevin Harrison 
Mary Badham
Mary Badham
Chrissie 
Pat Cardi
Pat Cardi
Barnaby Harrison 
Robert Pickering
Robert Pickering
Travis 
Linda Lawson
Linda Lawson
Justine 
Ref Sanchez
Ref Sanchez
Ketchman