The Local Government Association (LGA) has warned that people need to be more aware of modern slavery, after figures have shown council referrals of potential victims have soared by 78 per cent.
The LGA and fire and rescue services has made the comment after undertaking major operations to rescue workers being paid as little as £1 an hour and sleeping on cardboard.
The operations involved shitting down suspected brothels, making arrests and securing convictions after car wash operators, nail bars and fast food outlets were all visited.
The LGA is urging the public to look out for tell-tale signs, such as large numbers of people being ferried to and from properties in vans or minibuses early in the morning and returning late at night.
Cllr Simon Blackburn, Chair of the LGA's Safer and Stronger Communities Board, said: "Modern day slavery is a rising threat to our communities, and because of its hidden nature, is a major concern.
"Criminal gangs are making large sums of money on the back of others' misery by forcing people – often by threatening or using physical violence - to work for little or no pay, or to pay off outstanding debts. By contrast those taking advantage of these people are often living luxury lifestyles.
"Councils are determined to identify these ruthless profiteers and rescue their victims from lives of servitude – and communities can really play a big part to help.
"People should look out for tell-tale signs, like large numbers of people staying in homes and people being taken to and from the address in vans or minibuses early in the morning and returning late at night. If you are using a car wash, look at whether people working there have clothes that protect them from the strong chemicals being used.
"Tip-offs from communities can help councils work with partners to better tackle slavery and exploitation. A simple phone call could make a world of difference to people living wretched lives at the hands of heartless gangmasters."