There are worries there are hundreds of women being held in Bristol who are being used for the sex trade.
Recent estimates suggest there are 72 so-called 'safe houses' in the city, and up to 300 women could be victims of trafficking.
Workers at womens centre Platform 51, based at Knowle West Health Park, say an investigation has begun into the possibility that there is an influx of women being moved here from the Czech Republic as they have noticed an increase in the numbers of foreign workers on the streets of Bristol.
Cezara Nanu, General Manager of Platform 51, says they are kept hidden and cannot integrate into society: "We have found that some of the women we have helped do not even know how to say 'hello' in English, so they would find it very hard to get by.
"Society in general stereotypes them and pushes them aside as they are in the sex trade.
"We are helping some women who we are trying to identify if they are being trafficked. They do not speak English, and seem not to know about contraception and how to stay safe."
Click below to hear more of our reporter Alex Hulse's interview with Cezara Nanu: