Three men, aged 53, 38 and 20 years old from the St Brides area of Newport, have been arrested on suspicion of slavery and servitude offences, Gwent Police said.
Four other suspects remain in custody and are assisting officers with their enquiries after the granting of a further 24 hours in custody by a District Judge.
More top news
Stars appeared in black as they called for an end to harrassment at the UK's film awards night.
The family of Alfie Dingley, 6, have been refused permission to legally use the drug to help control his seizures.
Part of the message read: “I don’t give a s**t if the whole street collapses”.