- Country: UK, West Germany
- Genres: Comedy, Crime, Drama
- Release: 1967-05-01
- Director: Cyril Frankel
- Writers: Derry Quinn , Stanley Munro
- Language: English
- Stars: Stewart Granger , Susan Hampshire , Cathleen Nesbitt , James Culliford , Brigitte Horney , Robert Morley (I) (1908–1992) , Sophie Hardy , Colin Gordon , Eddi Arent , Diane Clare , Diane Clare
- Runtime: 88 min
- Awards: N/A
- AKA: Le Signe du trigone (France, French Republic) , La planque (France, French Republic) , 大強盗団 (Japan) , Het geheim van de witte non (Netherlands the) , Trígono de muerte (Mexico) , To recital tou eglimatos (Greece) , Valkoisen nunnan salaisuus (Finland) , Edgar Wallace: Valkoisen nunnan arvoitus (Finland) , Sob o Signo da Suspeita (Portugal, Portuguese Republic) , El templo del hampa (Spain) , The Trygon Factor , Secretul calugaritelor in alb (Romania) , Det stumma vittnet (Sweden) , Le signe du trigone (Canada) , Død mand sladrer ikke (Denmark) , Le signe du Trigorne (France, French Republic) , The Trygon Factor (Canada) , Dai gôtô-dan (Japan) , Das Geheimnis der Weissen Nonne , The Trygon Factor (United States of America) , La grande sfida a Scotland Yard (Italy) , Kolmiokierre (Finland) , Dişi Canavarlar (Turkey) , A fehér apácák titka (Hungary) , The Secret of the White Nun , Tajna bele opatice , Factor One (United Kingdom) , Das Geheimnis der weißen Nonne , O Triângulo Mortal (Brazil) , The Trygon Factor (United Kingdom)
- Plot: A Scotland Yard detective is investigating a string of robberies and a murder, and the information he uncovers leads him to the estate of a wealthy but strange English family, who share their mansion with a group of nuns. The detective comes to suspect that neither the family nor the nuns is quite what they seem to be.
- IMDB:tt0061124
The Trygon Factor Cast · · · ALL
Cyril Frankel
Director
Stewart Granger
Superintendent Cooper Smith
Susan Hampshire
Trudy Emberday
Cathleen Nesbitt
Livia Emberday
James Culliford
Luke Emberday
Brigitte Horney
Oberin
Robert Morley
(I)
(1908–1992)
Hubert Hamlyn
Sophie Hardy
Sophie
Colin Gordon
Dice
Eddi Arent
Clossen
Diane Clare
Clare
Allan Cuthbertson
Det. Thompson
Caroline Blakiston
Nun
Richardina Jackson
Nun
Conrad Monk
Pasco
John Barrett
(III)
(1910–1983)
Guide
Jeremy Hawk
Bank Manager
James Robertson Justice
Sir John (voice)
Joseph Cuby
Inigo Jackson
Russell Waters
Tom Bowman
Carmen Dene
Carol Dilworth
Siegfried Schürenberg
Sir John