Detecto Puzzles.

Marketed by Austin Project Management, in London's Marylebone Road, this series of six, 500 piece cardboard jigsaw puzzles add an interesting dimension to their enjoyment in that each contains a whodunnit style mystery short story, providing lots of clues to unravel along the way and potential suspects involved in each of the crimes featured. The fictitious authors names form another humorous facet to the series.
The reverse side of each bookshelf-style box lists the other five titles available and records 1975 copyright details, also quoting them to have been Made and Printed in Great Britain.
A leaflet contained in the puzzle A Shot in the Dark, promotes the series along with other products including puzzles from the TV series; Kojak and The Sweeney, plus the motion picture Jaws.
Many thanks to Alan Sudbury for his efforts in detailing and photographing the puzzles.