A group that calls itself "Men’s Rights Edmonton" has claimed responsibility for posters claiming some women lie about sexual assault.

After a story aired about the controversial posters on Tuesday, CBC News received an email from an unknown member of the group.

"Thank you for your interest in our activist group," the person going by the name MR-E wrote. "Yes, we have been very busy with postering our town."

The posters, which mimic the well-known "Don’t be that guy" campaign against sexual assault, recently popped up in downtown Edmonton and around the University of Alberta, where they have since been taken down by campus police.

The "Don’t be that girl" poster reads: "Just because you regret a one night stand, doesn’t mean it wasn’t consensual. Lying about sexual assault = a crime."

Karen Straughan, spokesperson for Men’s Rights Edmonton, believes the original "Don’t be that guy" campaign demonized men.

"It frames all men as potential sexual predators," she said.

Lise Gotell, chair of women and gender studies at the University of Alberta, worked on the original "Don’t be that guy" campaign. She believes the new posters send the wrong message.

"They've perverted the message," she said. "And they've transformed it into a rape apologist message and it's just very disturbing."

Police officers who investigate sexual assault cases say false accusations are "extremely rare."

"I was sexual assault detective for 4½ years and in that time I only dealt with one, and I dealt with numerous files. Many, many, many files," said acting Insp. Sean Armstrong from the serious crimes branch of Edmonton Police.

"So they are extremely rare."

Police fear the posters will deter victims from speaking out.

"We want to encourage people to come forward and report these horrendous crimes," Armstrong said.

"So to demean these crimes and put them down and belittle them goes against that."

Organizations involved with the original anti-sexual assault campaign will discuss what action they might take in response to the "Don’t be that girl" posters.