Seven locations raided after Al Jazeera documentary on alleged slavery at car washes prompted police action.

British police have arrested three people in pre-dawn raids as part of an operation against a suspected organised slavery ring in the southern county of Kent.

Wednesday’s raids were carried out simultaneously at seven different properties in Canterbury and Maidstone after an investigation prompted by an Al Jazeera documentary Britain’s Modern Slave Trade .

The operation targeted car washes and residential addresses and resulted in the arrests of two men, aged 32 and 36, and a 21-year-old woman.

The documentary, broadcast earlier this year, contained undercover footage spread over several months of conditions at a car wash.

INTERACTIVE: Britain’s Modern Slave Trade

In a statement published after the raid, Kent Police said they were working on identifying potential victims and what crimes may have been committed.

Police were “speaking to around 15 potential victims to identify if offences of trafficking, modern slavery or money laundering have been committed”, the statement read.

Superintendent Eddie Fox from Kent Police said the operation was the culmination of months of investigative work.

“We have worked closely with our partners at the NCA [National Crime Agency] and Immigration Enforcement as part of this operation and would ask anyone who may have information that may prove useful to this investigation, to come forward,” Fox said.

Fox confirmed to local news website Kent Online that the Al Jazeera documentary had prompted the police’s investigation.

“We hadn’t known about this before the documentary – that started the investigation,” he told the website.

More than 80 officers were involved in the raids, Kent Online reported.

Al Jazeera’s Director of Investigative Journalism Clayton Swisher said about 20 people were freed from captivity in the UK following the documentary was broadcast.

“Beyond the headlines this film created, possibly 20 slaves have now been freed from their captivity in Britain and are in safe custody,” he said.

“As journalists, we feel incredibly gratified, and we wish to thank British law-enforcement officials for treating these allegations with the utmost seriousness. It seems that we only scratched the surface on the scale of what was taking place.”