A suspected crime gang accused of keeping migrants as slaves to run cannabis farms has been targeted in dawn raids.
Officers from the National Crime Agency (NCA) went to a number of addresses in London on Wednesday and arrested three men on suspicion of modern slavery, human trafficking and cannabis production offences.
Two others, a man and a woman, were arrested on suspicion of immigration offences.
The raids follow an operation in April last year targeting a cannabis farm in an industrial unit in Stroud, Gloucestershire, where three Vietnamese nationals were found having been forced to work.
Around 500 plants with a street value of more than £400,000 were discovered at the site, and later destroyed.
A man aged 34 and a woman aged 28 were arrested in Essex in June on suspicion of having set up the farm and were released under investigation.
NCA senior investigating officer Neil Gardner said: “Our investigation has uncovered a criminal network we believe to be involved in setting up cannabis farms, and staffing them with the victims of modern slavery and human trafficking.
“Three individuals have already been safeguarded, but it is likely there were more victims we don’t yet know about.
“These types of criminal gangs exploit others for profit, pure and simple.
“Modern slavery is often difficult to tackle because the victims don’t always recognise they are being exploited, which is why we need the public’s help.
“I’d ask anyone who sees something they don’t feel is right to report it. It might be someone seeming afraid, vulnerable or controlled, moved around against their will. These are all signs of exploitation.”
The raids on Wednesday took place in Rochester Way, Blackheath; Turnham Road, Lewisham, and Old Kent Road, New Cross, all in south-east London, and Temple Avenue in Dagenham in east London.
Anyone with suspicions about modern slavery can contact their local police force on 101 or the Modern Slavery Helpline on 08000 121700.
