Sounds like the
Travis Walton Abduction. He was allegedly abducted and it was some weird UFO group that picked him up when he reappeared naked and shivering days later. First thing they wanted from him was a large urine sample. WTF ?? Later a movie was made and the encounter only barely resembled what he initially said happened to him.
That does nothing to add credibility.
This is one of those cases with opinions all over the place, some feel Walton is sincere and of good character and should be believed. He has made himself a regular at UFO conventions and so forth. In my opinion he may be a nice guy but there are inconsistencies that make me pretty skeptical of this one.