B.C. police are seeking more witnesses after a second arrest was made in connection with an alleged teenage gang rape, which was photographed at a rave and then spread on Facebook.

RCMP officers recently made a second arrest in the case, which occurred at a party near Vancouver last week, but Insp. Derren Lench said more witnesses need to speak with investigators.

"There's still many more that police need to speak to, and we still want these people to come forward," he told reporters on Friday afternoon.

This follows the Thursday arrest of a boy believed to have distributed photos of the assault.

The RCMP say the pictures of the rape have spread like wildfire through social networking sites and cellphones, despite attempts by police and the victim's family to stop them.

Investigators in the community of Pitt Meadows have been on the hunt for seven men and youths photographed assaulting the 16-year-old student, whom they say was likely given a date rape drug before the attack last Friday night or early Saturday.

The second suspect was arrested Friday morning, and may be one of the seven involved in the assault, said Lench.

Both suspects have been released; neither has been charged.

Lench noted that toxicology results were expected to confirm that the victim was under the influence of drugs at the time of the incident.

The arrest linked to the photos is "a bit of a veiled threat," CTV's Rob Brown reported Friday.

"I've talked to some former Mounties who say it really is more of a scare tactic and probably a wake-up call directed at the parents even more so than the teens, who up to that point, haven't been getting the message."

Brown also reported that more arrests are expected, as police ramp up their investigation.

Plus, negligence charges may be launched against the owner of the property where the party occurred, Brown said.

Meanwhile, the girl's father told CTV British Columbia that his daughter has only vague memories of the attack, but has seen the pictures.

"The rape continues" through the photos and comments on Facebook, which insinuate the sex was consensual, the father said Friday.

The father urged parents to search their children's computers and cell phones to delete any pictures of the rape. "It's the moral and ethical thing to do," he said.

RCMP officers planned to visit the four high schools in Maple Ridge on Friday to warn students that distributing or downloading those pictures -- which have already been widely shared via cell phones and the Internet -- is a crime.

Earlier Friday, a former sex crimes investigator said anyone who posts pictures or video of the gang rape of the teen to the Internet, is not only re-victimizing the young woman, but committing a criminal offence.

Retired Det.-Sgt. Dave Perry, formerly of the Toronto Police sex crimes unit, told CTV News that anyone who downloads or distributes the images could face charges.

"They're committing a criminal offence because they're making and distributing child pornography, so they are committing a criminal offence. Anyone who downloads, saves it or distributes it in anyway is the subject of a criminal charge," Perry said.

The crime, and the fact it is being distributed so rapidly despite pleas from investigators, is among the worst offences he has seen, Perry said.

"The most heinous act you can do to somebody is re-victimize them a second, third and fourth time and so on, and of course with the Internet that's exactly what's going to happen unfortunately for this poor young woman."