John Creasey was a one man novel factory, writing (according to Wikipedia) over 600 novels under 28 different names.  Upper class detective Richard Rollison  (aka ‘The Toff’) featured in over 40 novels, though the BBC have only dramatised 2 of these.

The Toff on the farm

Monty Morne, an old friend of Richard Rollison, tries to persuade The Toff to buy a farm from some friends of his, brother and sister Alan and Gillian Selby. But on arriving at Selby Farm, they discover that Alan Selby has been kidnapped and Gillian has been made offers for the farm that are much more than it is worth.

Rollison is drawn into the mystery when one of the bidders and his accomplice are found murdered, with the other bidder, William ‘Tex’ Brandt, suspected of the crimes.
The Toff has to discover the secret of Selby Farm and why rival bidders are seemingly prepared to kill for it, despite the presence of a sitting tenant who refuses to leave. 

The Toff and the Runaway Bride

The Honourable Richard Rollison reluctantly agrees to attend a wedding. Is he the only one that notices something strange about the bride? Murder and blackmail follow with Rollison seeking a first wife, a discovery in the Thames, and him as a suspect. He is Paris bound when the police stop him, but that is not allowed to get in his way as he attempts to solve the mystery and reveal the murderer’s identity.