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.
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The parents of Maya Kantengule, 7, have paid tribute to their daughter who was found at the bottom of the pool at a friend's birthday party.
Staying unsettled over the next few days, with showers or longer spells of rain