Four people have been arrested in a series of major armed police raids involving more than 100 officers at addresses allegedly linked to slavery.
Gwent Police and the Serious Organised Crime Agency (Soca) targeted addresses in Cardiff, Penhow in Monmouthshire, and Marshfield, Newport, in South Wales.
A 66-year-old man and a woman, 42, both from Marshfield, a Cardiff man, 36, and a woman, 42, from Penhow, all remain in custody assisting police with enquiries.
Forensic teams are searching the Marshfield site on the strength of “intelligence” suggesting the body of an unknown person may be buried there.
An East European man was also taken from the Marshfield address to hospital for assessment of his physical and mental condition.
The raids yesterday were triggered by the discovery of another man living in poor conditions at the Marshfield location earlier this year.
The Gwent Police investigation, codenamed Operation Imperial, has seen the force team up with Soca, the UK Human Trafficking Centre, the RSPCA, and the Red Cross.