UPDATE: 2.02pm

Chief Inspector Huw Nicholas said at a press conference outside the Cariad Farm today: “Clearly the welfare of people that may be held in terrible conditions is our paramount concern, so any information we get it’s absolutely central we act on.

“An investigation like this is very complicated. As things go on, we don’t know what we’re going to find. With slavery enquiries, we’re talking about people that have been living in very poor conditions working for no money for some considerable length of time.

"There are all sorts of questions that need to be raised and addressed and of course the exact detail of that will form part of the investigation.

“You’ll see from the activity behind me there’s no sign of us leaving the site at this point. The reason for that is the excavation has been larger than we expected. There’s quite a lot of material for us to work through with the forensic archaeology team.

He stressed: “We’re still appealing for the writer of the anonymous letter to come forward. We think they have vital information, central to this investigation.”

Anyone with information is asked to contact police on 101 quoting log 66 23/09/13. Alternatively they can call Crimestoppers, which is independent of the Police and guarantees complete anonymity, on 0800 555 111.

listen to ‘Jen Mills talk about Ch Insp Huw Nicholas on latest in Gwent slavery probe’ on Audioboom

UPDATE: 10.05am

GWENT Police have found a third man in their investigation into slavery this morning.

The 60-year-old man was recovered from one of the sites and was taken to a medical reception centre where his physical and mental condition can be assessed by specialist British Red Cross staff. Police say he is a British national.

Police have also made three more arrests this morning.

Three men, a 53-year-old, a 38-year-old and a 20-year-old, all from the St Brides area of Newport, were arrested on suspicion of slavery and servitude offences.

Senior Investigating Officer Detective Superintendent Paul Griffiths said:

“I’m still appealing for anyone with any information to contact us on 101 quoting log 66 23/09/13 . Alternatively if anyone has information and would rather not pass this directly to the Police then I would urge them to contact Crimestoppers, which is independent of the Police and guarantees complete anonymity, on 0800 555 111. They don’t need to give their name and the Police will never know who they are. Any information given would be passed to the team in complete confidence.

“I’m also again making a personal plea to the author of an anonymous letter which was sent to another Police Force making certain allegations and providing information relevant to this enquiry to contact. We believe they may have information which could greatly assist us.”

The search of around a farm in Peterstone continues today with specialist officers, equipment and a forensic archaeologist searching for a body which may have been buried at the site. Police say this phase of the operation is likely to continue into the weekend.

Four people remain in custody following the granting of a further 24 hours in custody by a District Judge.