Calgary police have charged three people in connection with a human trafficking and prostitution investigation.

It all started when a 37-year-old woman reported she had been physically and sexually assaulted while working in the sex trade.

"A man, who was acting as her pimp, allegedly forced her to have sex with him, as well as other clients, between August and October 2013," said police in a release.

A 26-year-old Calgary man was arrested in March and charged with human trafficking, receiving material benefits from trafficking a person, two counts of choking, three counts of sexual assault, living on the avails of prostitution and assault causing bodily harm and assault. He is set to appear in a Calgary courtroom on June 13.

The same victim also told police she had been forced to work for two other people between June and August 2013.

That complaint led to charges against two others, and they are expected to appear in court June 17.

A 30-year-old Calgary man has been charged with human trafficking, receiving material benefits from trafficking in a person, living on the avails of prostitution, assault and aiding, abetting or compelling a person into prostitution.

A 25-year-old woman has also been charged with human trafficking, receiving material benefits from trafficking in a person, living on the avails of prostitution and aiding, abetting or compelling a person into prostitution.