Nilrem

From Memory Alpha, the free Star Trek reference.

Nilrem was a medical doctor on Malcor III.

In 2367 he treated William T. Riker, who was disguised as a Malcorian, after he was injured during a surveillance mission. When he discovered physical differences between Riker and Malcorian physical aspects, he informed the minister of internal security. Nilrem was ordered by the minister to wake Riker, although this was a medical risk. He did so and was promoted to director of the medical facility. (TNG: "First Contact")

Nilrem was played by Steven Anderson. The name is Merlin spelled backwards.