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
A daring hippopotamus escaped its circus and gave motorists a fright when it plodded into the road.
The Scottish flat has a lounge, kitchen, family bathroom as well as three bedrooms, and could eventually be sold for up to £30,000.
Spoilt with more springtime sunshine