A politician's speech is interrupted by the discovery of a woman's body in the Thames - London County Hall, Belvedere Road, London SE
The pub where Dick Blaney (Jon Finch) and Babs (Anna Massey) work - The Globe, 37 Bow Street, London WC2
The pub where Dick Blaney overhears people discussing the necktie murders - The Nell of Old Drury, 29 Catherine Street, London WC2
View of Covent Garden - Henrietta Street, London WC2
Brenda Blaney's matchmaking agency was located in Dryden Chambers. That passage no longer exists but the archway and iron latticework at 119 Oxford Street, London W1 still marks the old entrance.
Brenda Blaney's home - 31 Ennismore Garden Mews, London SW7
Dick Blaney is waiting for Babs - Leicester Square, London WC2
The Coburg Hotel - Hilton Hyde Park, 129 Bayswater Road, London W2
Blaney swears to Babs that he's not a murderer - Hyde Park, just opposite London Hilton on Park Lane
Blaney goes to see his army pal - London Hilton, 22 Park Lane, London W1
New Scotland Yard, 8-10 Broadway, London SW1
Bob Rusk's (Barry Foster) flat - 3 Henrietta Street, London WC2
The truck stop where Bob Rusk gets out of the potato truck was Wally's New Café. It was once located on North Western Avenue, Watford, Hertfordshire WD25, off A41 near Hartspring Lane. It was later replaced by a modern superstore.
The prison where Blaney is taken - HMP Wormwood Scrubs, Du Cane Road, London W12
Blaney is transported to a hospital - St. Mary Abbott Hospital, Marloes Road, London W8. The hospital closed in 1992, and most of its buildings were demolished, but much of the original main building (seen in the background of the screenshot) survives. The site was redeveloped into a luxury housing complex called Stone Hall Gardens. It's a gated community and the access is limited to its residents.