Jack Hawkins ( Jack Hawkins )

Supt Tom Halliday

John Stratton ( John Stratton )

Sergeant Ward

Dorothy Alison ( Dorothy Alison )

Mary Halliday

Michael Brooke ( Michael Brooke )

Tony Halliday

Sam Kydd ( Sam Kydd )

Police Constable in Information Room

Glyn Houston ( Glyn Houston )

Detective Sergeant in 'Q' car

Richard Leech ( Richard Leech )

Nightwatchman / Gilson

Newton Blick ( Newton Blick )

Deputy Commander

Geoffrey Keen ( Geoffrey Keen )

Chief Superintendent Jim Malcolm

Sydney Tafler ( Sydney Tafler )

Stone

Peter Burton ( Peter Burton )

Creasey

George Rose ( George Rose )

Slob

Arthur Rigby ( Arthur Rigby )

Detective Inspector at Chester

Ralph Truman ( Ralph Truman )

Colonel Blenkinsop

Ian Bannen ( Ian Bannen )

The Young Workman - Stanley James

Maureen Davis ( Maureen Davis )

The Young Workman's Wife - Mrs. James

John Warwick ( John Warwick )

Detective Inspector at Shipping Office

Joss Ambler ( Joss Ambler )

Cashier at Shipping Office

Barry Keegan ( Barry Keegan )

Detective Constable in Hospital Ward

Alec McCowen ( Alec McCowen )

House Surgeon

Harry Locke ( Harry Locke )

Secondhand Dealer

Nicholas Parsons ( Nicholas Parsons )

Police Constable Bates

Warwick Ashton ( Warwick Ashton )

Newspaper Circulation Manager

Ursula Howells ( Ursula Howells )

Mrs. Elliot / Mrs. Gilson

David Davies ( David Davies )

Welsh Police Constable

Julie Milton ( Julie Milton )

Welsh Newsagent's Daughter

Meredith Edwards ( Meredith Edwards )

Mr. Thomas

Harold Goodwin ( Harold Goodwin )

Official at Somerset House

John Welsh ( John Welsh )

House Agent at Shepperton

Gillian Webb ( Gillian Webb )

Housewife at Shepperton

Maureen Delaney ( Maureen Delaney )

Mrs. Stevens, the daily help

Jameson Clark ( Jameson Clark )

Detective Superintendent Ogilvie

William Mervyn ( William Mervyn )

Manager of Festival Hall

Vincent Ball ( Vincent Ball )

P.C. at Hospital (uncredited)

Richard Davies ( Richard Davies )

Detective (uncredited)

Frazer Hines ( Frazer Hines )

Urchin (uncredited)

Stratford Johns ( Stratford Johns )

Constable (uncredited)

David Lodge ( David Lodge )

Detective at Car Lot (uncredited)

Guy Standeven ( Guy Standeven )

Detective (uncredited)

Frederick Treves ( Frederick Treves )

Detective tailing Creasey (uncredited)

Peter Welch ( Peter Welch )

CID Man (uncredited)

Martin Wyldeck ( Martin Wyldeck )

Officer in Criminal Records Department (uncredited)

Dennis Carnell ( Dennis Carnell )

Edward Cast ( Edward Cast )

Michael Collins ( Michael Collins )

Fred Davis ( Fred Davis )

Jack Dearlove ( Jack Dearlove )

Robert Gregory ( Robert Gregory )

Fred Griffiths ( Fred Griffiths )

Patrick Halpin ( Patrick Halpin )

Aidan Harrington ( Aidan Harrington )

George Holdcroft ( George Holdcroft )

Lindsay Hooper ( Lindsay Hooper )

Arthur Howell ( Arthur Howell )

Colin McKenzie ( Colin McKenzie )

Jack McNaughton ( Jack McNaughton )

Robert Moor ( Robert Moor )

Fred Nicholas ( Fred Nicholas )

John Paul ( John Paul )

Roy Purcell ( Roy Purcell )

Charles Rayford ( Charles Rayford )

Anthony Richmond ( Anthony Richmond )

Pat Ryan ( Pat Ryan )

Philip Stewart ( Philip Stewart )

Meadows White ( Meadows White )

John Wilder ( John Wilder )

Sonnie Wills ( Sonnie Wills )