An app that allows people to anonymously report possible slavery at car washes received hundreds of reports in the first five months after it launched.

Between June and December last year, the Safe Car Wash app received over 2,200 entries, of which 41 per cent (930) were deemed likely to be modern day slavery after users were asked a series of questions.

The pioneering app allows drivers to go through a check list of possible evidence of slavery or exploitation at hand car washes, which have exploded across the UK in the last 10 years. 

Drivers are asked to look out for things like child workers, the absence of protective clothing like boots and gloves, and evidence of people living on site as possible signs of slavery or exploitation. 

Other possible indicators include being asked to pay by cash or to give the payment to the manager, and whether the car wash cost less than £6.70. 

Research by the University of Nottingham's Rights Lab found that in nearly half of the reports (48 per cent), app users said workers did not have access to suitable protective clothing, despite the fact that many hand car washes use harsh chemicals. 

Four in five users reported that the car wash had a cash-only policy, while nearly one in 10 (8 per cent) reported children working on site. Fourteen per cent said there were signs that people were living on site and 17 per cent said workers looked fearful. 

Users who were told by the app that slavery was likely were asked to call the Modern Slavery Helpline and their anonymised findings were shared in real time with police and the Gangmasters' and Labour Abuse Authority.

The app, which has so far been downloaded over 8,000 times, was launched jointly by the Church of England's anti-slavery Clewer Initiative in partnership with the Catholic Church's anti-slavery drive, the Santa Marta Group.

It was launched in response to the lack of reliable data on suspected exploitation at hand car washes in the UK. 

Bishop Alastair Redfern, Chair of The Clewer Initiative, said: "This research from the University of Nottingham's Rights Lab shows that the Safe Car Wash app has made an excellent start towards mapping the extent of modern slavery and labour exploitation in hand car washes, and, crucially raising public awareness of this issue.

"Sadly, the findings so far confirm what we already feared - that many car washes do not protect their workers.

"Our conversations with colleagues from law enforcement suggest that the data from the Safe Car Wash app is providing another piece in the puzzle of how to combat this complex crime. We hope to continue to build on this progress."

Bishop Patrick Lynch, from the Santa Marta Group, said: "I welcome this report into the results of the Safe Car Wash app. I hope the app and this report will help many people become much more aware of the exploitation that workers in the car washing sector often have to endure."

Dr Akilah Jardine, Research Associate at the Rights Lab, said: "Investigations and operations on hand car wash activities have identified the sector as a high-risk area for labour exploitation. Though often operating in plain sight, a great challenge in tackling abuses is the lack of data on the size and scope of the industry and the nature and prevalence of labour exploitation.

"The Safe Car Wash app shows the potential value of using technology in raising public awareness and leveraging the real life experience and insight of the community to improve our understanding of the sector and also gather the intelligence required to lead effective investigations."

The Church of England is asking drivers to check:

Do the workers have access to suitable protective clothing? Look out for gloves and boots.
Is there evidence of workers living on site? Can you see a caravan or mattresses and bedding?
Does anyone appear controlling or intimidating?
Does the body language of the workers appear withdrawn or fearful?
Do there appear to be minors working at the car wash?
Did you pay less than £6.70 for the car wash?
Does the car wash only accept cash?
Did they offer a receipt?
Did you have to pay the manager?