Researchers have found street sex workers are safer in Christchurch than Auckland.

A collaborative feature penned by a number of authors examined the factors which affect the likelihood of prostitutes experiencing violence as well as theft and threat by clients.

It found alcohol and drug dependency double the risk of violence in the industry.

Dr Laura Meriluoto from the University of Canterbury says, sex workers in Auckland tend to be more spread out, while in Christchurch, they tend to be in one area.

"It's quite concentrated around just Manchester St, and we think that could be one of the reasons why fewer sex workers are subjected to violence."