Five arrests were made, and various properties were searched, as part of a NCA investigation into a group suspected of using forced labour to produce cannabis.
Two individuals were arrested in Romford for slavery and possession of Class A and B drugs. A further two people were arrested in Birmingham on suspicion of production and possession of Class B drugs and immigration offences.
All four were released under investigation, whilst the fifth individual, who was arrested in Romford for immigration offences, remains in custody.
In its press release, the NCA confirmed its commitment to tackling modern slavery and noted that this type of criminality was driven by organised crime groups of low sophistication exploiting vulnerable people, often through extreme violence.
NCA press release