U375 crew - Officer diplomat

[timbird]

My 92 year old father was an officer on HMS Manxman during the mid sixties and tells the story of a small boat coming alongside whilst moored in Thailand, the Manxman was then based in Singapore.
In the boat was a German diplomat, based in Thailand, my father thinks he might of been the ambassador to Thailand, he requested to come aboard Manxman, and my father as officer of the watch welcomed him aboard.
He then introduced himself and stated he was aboard the uboat that torpedoed Manxman in December 1942 and out of curiosity would like to see the ship. They enjoyed the day together and inspected where the impact most likely was and in fact later invited my father to the diplomatic residence for a dinner. However my father is unable to recall the name of the ex Kriegsmarine officer but has fond memories of their unusual encounter. I have tried to find details of the crew of the German submarine involved using the Marine Archive resource and uboat.net but have been unable to tie off this story. Have you heard of a submariner who later becoming a diplomat, or attached to a trade mission or similar in Thailand ? - I would like to discover the name of this officer, to complete the story for my fathers memoirs.