The Long Arm

Supt Tom Halliday

Jack Hawkins

Sergeant Ward

John Stratton

Mary Halliday

Dorothy Alison

Tony Halliday

Michael Brooke

Police Constable in Information Room

Sam Kydd

Detective Sergeant in 'Q' car

Glyn Houston

Nightwatchman / Gilson

Richard Leech

Deputy Commander

Newton Blick

Chief Superintendent Jim Malcolm

Geoffrey Keen

Stone

Sydney Tafler

Creasey

Peter Burton

Slob

George Rose

Detective Inspector at Chester

Arthur Rigby

Colonel Blenkinsop

Ralph Truman

The Young Workman - Stanley James

Ian Bannen

The Young Workman's Wife - Mrs. James

Maureen Davis

Detective Inspector at Shipping Office

John Warwick

Cashier at Shipping Office

Joss Ambler

Detective Constable in Hospital Ward

Barry Keegan

House Surgeon

Alec McCowen

Secondhand Dealer

Harry Locke

Police Constable Bates

Nicholas Parsons

Newspaper Circulation Manager

Warwick Ashton

Mrs. Elliot / Mrs. Gilson

Ursula Howells

Welsh Police Constable

David Davies

Welsh Newsagent's Daughter

Julie Milton

Mr. Thomas

Meredith Edwards

Official at Somerset House

Harold Goodwin

House Agent at Shepperton

John Welsh

Housewife at Shepperton

Gillian Webb

Mrs. Stevens, the daily help

Maureen Delaney

Detective Superintendent Ogilvie

Jameson Clark

Manager of Festival Hall

William Mervyn

P.C. at Hospital (uncredited)

Vincent Ball

Detective (uncredited)

Richard Davies

Urchin (uncredited)

Frazer Hines

Constable (uncredited)

Stratford Johns

Detective at Car Lot (uncredited)

David Lodge

Detective (uncredited)

Guy Standeven

Detective tailing Creasey (uncredited)

Frederick Treves

CID Man (uncredited)

Peter Welch

Officer in Criminal Records Department (uncredited)

Martin Wyldeck

Dennis Carnell

Edward Cast

Michael Collins

Fred Davis

Jack Dearlove

Robert Gregory

Fred Griffiths

Patrick Halpin

Aidan Harrington

George Holdcroft

Lindsay Hooper

Arthur Howell

Colin McKenzie

Jack McNaughton

Robert Moor

Fred Nicholas

John Paul

Roy Purcell

Charles Rayford

Anthony Richmond

Pat Ryan

Philip Stewart

Meadows White

John Wilder

Sonnie Wills