New pictures of missing British tourist Tom Billings released

Investigators are renewing a public appeal for information about 22-year-old Tom Billings, who disappeared one year ago while travelling in Vancouver.

Police have released new family photos of the young man, hoping that someone will remember seeing him.

"Every day is very difficult," says Billings' father Martin, who lives in Oxford, U.K., and visited Vancouver six weeks ago to discussthe ongoing search effort and release of the photos with police.

"We still hope for the impossible, or maybe the improbable, I should say. But it's a very bleak picture, I'm afraid," he said.

Last spotted on North Shore hiking trail

Tom Billings was last seen one year ago today.

Two hikers told North Shore Search and Rescue they talked with the young man at about 1:30 p.m. PT on Hanes Valley Trail, a difficult hiking route in Lynn Headwaters Regional Park in North Vancouver.

Police say he wasspotted earlier that day on East Broadway near McLean Drive, at about 9:00 a.m.

However, he wasn't reported missing until seven to 10 days later, when he failed to complete travel plans on his eight-week tour of North America.

Billings' disappearance triggered a major trail and helicopter search of Vancouver'sNorth Shore mountains last year with investigators asking for the public's help to comb over aerial video.

"The thing I don't understand...is simply how in the First World, someone can disappear...when we're all connected 24hours a day," says Billings' father.

The search for Tom has continued,most recently in early October, says Martin Billings, who praises the efforts of the Vancouver Police and the North Shore Rescue team.

"Sadly it's all been in vain, but it's not for want of trying."

A meticulous planner

Vancouver Police call it "very unusual," for a young man to disappear with no resolution or suspicion of foul play.

Const. Brian Montague said thatout of thousands of missing persons reports, "I believe this is the only one in the last couple of years that has remained unsolved."

Montague describes Billings as an avid hiker, whohad travelled all over the world.

Billings' father exchanged emails with him 48hours before he disappeared, and says he seemed "lighthearted" and eager to visit Canada for the first time.

Martin Billings described his son as a meticulous planner, who had been hitchhiking and finding accommodation on Couchsurfing.com during his trip. His laptop and backpack were left behind where he was staying on East Broadway.

Billings is described as white, five feet seven inchestall, 160 pounds, with blonde short hair and blue eyes. He was last seen wearing a black jacket and grey, military-style pants.

The VPD is asking anyone who believes they saw Tom Billings on or after Nov. 25, 2013 to call their Missing Persons Unit at 604-717-2530.