Koenig, 41, is a former star of the TV sit-com "Growing Pains" and the son of "Star Trek" icon Walter Koenig, who played Chekov in the original series.
His family reported him missing Sunday, a week after they had last heard from him. The younger Koenig, who suffers from depression, missed a scheduled Feb. 16 flight home to California from Vancouver without letting anyone know why.
Koenig's parents and sister have been talking to the media this week, pleading with the actor to call home and asking for anyone with information about his whereabouts to contact the authorities.
"For some reason unbeknownst to anyone, Walter Koenig, the father of the missing Andrew Koenig, and (Andrew's mother) Judy Levin-Koenig ... left the studio in Vancouver," E! News quoted King as saying on his CNN chat show "Larry King Live" Wednesday night. "We checked them out. They were prepared to go on. I said 'hello.' They said 'hello.' We said we'd be on in two minutes, they said 'fine.' And they got up and left for reasons unknown."