The actor who played Chekov in the original "Star Trek" TV series is pleading for help to find his son who vanished in Vancouver earlier this month.

Walter Koenig and his wife Judith arrived in the 2010 host city yesterday to help search for their 41-year-old son Andrew.

The California resident, best known for playing the role of Richard "Boner" Stabone on the TV sitcom "Growing Pains," was last seen at a friend's house in the area of Main Street and 25th Ave. on Valentine's Day.

Andrew's father said his son's emotional health may not be very good and he has lived with depression for his entire adult life. The last time he contacted his parents was on Feb. 9 after his mother had surgery.

"This has been a lifelong situation," Walter Koenig told reporters at a press conference Wednesday morning. He added that Andrew had been off his anti-depression medication.

"We think he's probably in a very depressed state," Judith Koenig said.

Andrew had recently begun selling some of his personal possessions and clearing out his apartment, his parents said.

"There was a pattern of closing out things, giving away things," Walter Koenig said.

The actor made a direct plea to his son:

"We just want to know that you're okay," he said, his voice breaking up.

"If that means changing your life and just staying here then okay, that's okay. You don't have to come back. Just let us know that's your intention."

Andrew Koenig arrived in the city Feb. 11 to visit friends. He was reported missing Feb. 18 – two days after he was scheduled to return home to Los Angeles.

The woman he had been staying with, a burlesque dancer with the stage name Jenny Magenta, told CTV News Tuesday night he was more quiet and reserved than normal during his stay.

Magenta said they had spent Feb. 14 visiting, and he left without saying goodbye the following day.

"It's weird he didn't give us a quick call," she said.

Vancouver police said Tuesday there had been no activity on his cell phone or bank records since Feb. 16.

"Police are still hopeful that Andrew will be found alive and safe," they said in a statement.

The search for Koenig has centred on Stanley Park, an area where he was known to enjoy walking.

"He felt at one with people here," Judith Koenig said.

Magenta said authorities also picked up a signal from his cell phone in that area.

Both Walter and Judith Koenig praised Vancouver police investigators for how they've handled the case.

"If the police force is any indication of the sensitivity and the congeniality and the warmth of the general population – and I'm sure they are – you've got a terrific citizenry in Vancouver," he told reporters.

"And I can understand why our son has always found this to be a second home, if not a first home for him."

Andrew Koenig first came to Vancouver in the early 1990s for a guest role on the television show "21 Jump Street." His father said he loved it so much he decided to live here for another three years.

He had recently been working as a camera operator on the comedy podcast "Never Not Funny."