Rimshi Ketuk - who was he?

My text refers to Rimshi Ketuk. Conceivably he is རིམ་བཞི་སྐྱིད་ཕུག་, or Rimshi Kyipug, but this latter does not appear to be known as a collaborator, while the Rimshi Ketuk in question was actively hunting those attempting to escape.

The “Rimshi” was a fourth-rank official in the former Tibetan government, while the Ketuk is concievably a rendering of སྐྱིད་ཕུག་ This would make him the person known as Rimshi Kyipup, but Rimshi Kyipup is not apparently known as having been a collaborator.

I see three possibilities: i) this is the right person, and his time as a Chinese collaborator has not come to light; ii) the identification is simply wrong, and it is some other fourth-rank official with a similar sounding name who was involved – the transcriptions of the Tibetan into a pronunciation for English-speakers are often woolly; iii) the whole idea that “Rimshi Ketuk” was in command of the Chinese soldiers was a mistaken rumour, started in the heat of what, after all, was effectively war, and not corrected over the years.

We may never know.