An "astonishing" rise in harmful Christian exorcisms is being partly driven by migrant communities, a think tank has warned.

A report by Theos, a think tank focusing on religion, found that experts were concerned that the "booming industry" in exorcisms was putting Christians' mental health at risk.

The report, which examines the relationship between Christianity and mental health, said: "Exorcisms are now a booming industry in the UK, with a number of interviewees noting the astonishing increase in demand – often, as one noted, in defiance of any actual rules or procedures put in place by any church."

It said that this industry was in part "driven by immigrant communities and Pentecostal churches which are very open about their exorcism services".

Research found that interviewees, including mental health chaplains and other Christians working in mental health, said that "in the vast majority of cases, the person in question was suffering with mental health issues which required psychiatric assistance."

Ben Ryan, a researcher at the think tank and the report's author, said: "There has been an increased focus in the Anglican church on exorcisms, and partially that's in response to increased demand. They have been getting more and more people calling them saying there's demand for this.