VICTORIA -- The Dunahee family had just arrived at the school grounds for a football game when small, freckled Michael, wearing a Teenage Mutant Ninja Turtles T-shirt and blue sneakers, ran off to a nearby playground, his mother remembers.

When Crystal Dunahee turned around moments later after taking Michael's little sister out of her stroller, he was gone.

That was 25 years ago. She hasn't seen him since.

"It's still raw," said Dunahee in an interview. "The grief is still there, no matter how many years have passed."

The disappearance of four-year-old Michael Dunahee on the afternoon of March 24, 1991, from Victoria's Blanshard Elementary School playground sparked one of the largest police investigations in Canadian history.

There have been numerous leads over the years, though none so far have provided any conclusive answers as to what happened that day.

In 2013, a Metro Vancouver man bearing a striking resemblance to an age-enhanced picture of Michael willingly offered a DNA sample for testing, but Victoria Police eventually concluded it didn't match that of the missing boy.

"We're finding it really hard to believe it's been 25 years and we still don't have answers," said Dunahee.

Still, the investigation remains open into how the blond-haired, blue-eyed youngster vanished without a trace.

"In a lot of cases ... that police deal with, it's usually that one piece of information that we're missing, and we're just hopeful that we receive that one tip that we need to bring closure to the family," said Const. Matthew Rutherford of the Victoria Police Department.

"Every file's an open file until there's adequate conclusion," he added. "It's still an active investigation."

The Dunahee family continues to believe, despite the pain that persists.

"It's like picking a scab off: you're going to open it up again, and you relive it over and over again," Dunahee said. "(But) the hope remains."