A teenage girl who was allegedly raped by at least one man during a B.C. rave says she's "devastated" that a sexual assault charge has been stayed against the only suspect and she is pleading with witnesses to come forward.

Police believe the teen was assaulted while partygoers watched and took photos at a September 2010 rave called "Another Night in Bangkok" in rural Pitt Meadows. She was 16 at the time.

On Tuesday, prosecutors announced that proceedings had been stayed against a man charged with sexually assaulting the teen because there was not enough evidence to secure a conviction.

The teen victim, who cannot be named, told reporters at a press conference Wednesday that the news came as a shocking blow.

"I'm devastated that this case did not proceed," she said.

She also stood firm in her accusations.

"There's no doubt in my mind that what happened to me on the night of Sept. 11 was a sexual assault. No one in their right state of mind, including myself, would let something like that happen willingly."

Crown prosecutors have a year to come up with evidence that they think will lead to a charge that sticks.

More than a year ago, police said that at least two men had sexually assaulted the young victim, but no other suspects have been charged to date.

Investigators believe as many as 12 people watched the assault, but say a "code of silence" among witnesses at the party stymied their work.

The victim and her father both say they strongly believe there are people out there with crucial information that could lead to more arrests, and are imploring witnesses to come forward.

"I'm asking you to please do this for my family," the father told reporters Wednesday.

"At some point in your life you will have to explain, perhaps to your own kids, to do what's right in life, and it's never to late to do that."

He was adamant that his daughter was sexually assaulted and absolutely did not consent to anything at the party.

"A person does not acquire injuries in the extent and manner she did by being consensual or willing," he said.

RCMP spokesman Sgt. Thiessen said investigators strongly believe more than one person participated in the assault.

"Our investigators are not going to give up and stop trying to acquire the evidence we know is out there," Thiessen said.

"We know that there are individuals out there that can provide significant information."

The man whose charge was stayed hasn't been convicted of anything and is presumed innocent of these allegations.

Only one conviction has been handed down in connection with the party. Earlier this month, a 17-year-old boy was sentenced to 12 months of probation after pleading guilty to one charge of distributing obscene material. The teen admitted that he took and shared photos of the alleged rape because he got caught up in the moment and didn't think his friends would believe what he'd seen.

One man is still facing charges; Dennis John Allen Warrington is accused of making and distributing child pornography.

With files from CTV British Columbia's Lisa Rossington