Mounties have arrested a second person in connection with the shocking alleged gang rape of a teenage girl in Pitt Meadows last weekend.

The suspect, an 18-year-old male, was taken into custody on Thursday night. Police say they will be recommending a charge of sexual assault.

His name is being withheld until charges are laid.

Mounties say five to seven male witnesses were present during the assault, which occured last Friday night or early Saturday at a teen rave party.

Investigators say the victim, who cannot be identified under the Youth Criminal Justice Act, was likely under the influence of a "date rape" drug before the attack.

Charges are also being considered against a 16-year-old suspected of taking the photos and uploading them to Facebook. He was arrested and released earlier this week.

RCMP officers plan to visit four Maple Ridge high schools on Friday to warn students that distributing or downloading the pictures is a crime.

Retired Det.-Sgt. Dave Perry, formerly of the Toronto Police sex crimes unit, told CTV's Canada AM on Friday 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."

The victim's father spoke to CTV News on Thursday, pleading to put an end to the spread of the photos. "The rape continues with all the photos and comments," he said. "It makes me sick."

"I want to appeal to parents to look at their kids' computers and cell phones. Delete these pictures if they have them, not for the fear of being arrested, but because it's the moral and ethical thing to do," he said.

RCMP Cpl. Jennifer Hyland said police were shocked by several comments posted online that suggested the act was consensual.

"I have never ever seen anything like it," Cpl. Jennifer Hyland told a Thursday morning press conference. "When we have the physical and medical evidence about the injuries this girl's suffered…it's disgusting to read what these youth are posting and even more disgusting that the photos are being shared and put onto more sites. I've never seen anything like it."

With files from CTV British Columbia's Jon Woodward

Watch CTV News at Five and Six for more on this developing story