It's shown in the episode "The Mind's Eye" that Klingon Ambassador Kell was a traitor in cahoots with the Romulan Empire.
Is there anything in the EU which speaks to what happened to the ambassador? He was to be searched by the Klingons for an E-band transmitter. Presumably, Kell was executed, though does anything state this absolutely? For all we know, an Organian saved his life at the last instant. Doubtful, but it is possible.