Andrew Koenig

Walter Koenig and Judy Levitt-Koenig, the parents of missing Growing Pains star Andrew Koenig, walked off Larry King Live minutes before they were to appear because of "personal reasons" and not case developments, they said on Walter Koenig's website.

The two were scheduled to appear via satellite on Wednesday's edition of Live and were miked up and introduced when they abruptly left the Vancouver set, leaving King confused.

Growing Pains star goes missing

"We checked them out, they were prepared to go on, I said 'hello,' they said 'hello,'" King said. "We said we'd be on in two minutes, they said 'fine.' And they got up and left for reasons unknown."

A source close to the network told TVGuide.com that the Koenigs were upset that they had to wait until after breaking news segments featuring King's exclusive interview with Toyota CEO Akio Toyoda and the whale attack that killed a Sea World trainer. Because Andrew Koenig's sister, Danielle Koenig, appeared on Live the previous day, the Koenigs were always going to be the last segment, and the scheduling was not a slight to them, the source added.

Kirk Cameron "praying" for missing Growing Pains co-star

"Our heartfelt thoughts and prayers are with them and we hope they find their son soon," a rep for Live said in a statement.

Prior to their aborted Live appearance, the Koenigs held a press conference at the Vancouver Police Department Wednesday afternoon, during which Walter Koenig, a Star Trek alum, appealed to his missing son.

Andrew Koenig's dad: "I just want to know you're OK"

"If it means you just want to stay here, that's OK," he said. "You don't have to come back. Just let us know that's your intention."

Andrew Koenig, 41, was last seen Feb. 14 during a trip to Vancouver. He was reported missing two days later when he did not return home to Venice, Calif., as scheduled.