David Suchet
Suchet portrayed Christie's detective Hercule Poirot 1998 to 2013, and in 1985 was a central character and unconventional love interest in Sharpe's "Blott on the Landscape". (Another actor, Geraldine McEwan, is also a link, having played Christie's Miss Marple as well as the other half of the love interest in "Blott on the Landscape").