Winnipeg police say it's difficult to investigate complaints sex-trade workers make about violent johns, especially when the complaints are made anonymously.

In the wake of a Winnipeg man's arrest in connection with the death of a sex-trade worker earlier this week, another prostitute told CBC News she had made several complaints to police after violent experiences with a john who she thought might have been the suspect.

Her calls were not addressed, she said.

"They pretty much were, like, well, you know what, you're a sex-trade worker — you should be expecting stuff like this to happen," said the woman, who went by the name Amanda.

Winnipeg police Staff Sgt. John Ormondroyd said police take the issue of violent johns very seriously.

"The members of our morals unit are out there seeing what's going on. If they see something themselves, they act," he said.

"But for the most part, I mean, this is something that happens in secrecy and seclusion somewhere, so we're not seeing what is going on. So we have to rely on the girl to come forward and say something, and … that just doesn't happen very often."

Police don't receive many complaints from sex-trade workers, he added, and when they do, they're often made anonymously.

"It becomes very difficult for us to act when the person doesn't want to actually come forward themselves or make an actual complaint," he said.

Police are trying to build relationships with the city's prostitutes so they can talk openly about problems they encounter, Ormondroyd said.

"We're trying to educate the girls that we are there to try and help them," he said.