Police hunt for body they fear was secretly buried by 'slavery gang' in Wales Police were tipped off to slaving activities after a 43-year-old man says he escaped a slave gang after 13 years Police then launched a series of raids this morning around Wales They arrested four people in connection with the investigation They then started combing nearby farmland They believe a body may have been buried there in secret Police are combing Welsh farmland in a hunt for a body they believe was buried in secret by a suspected slave gang. Officers have drafted in forensic archaeologists to search a plot in Marshfield, near Newport, South Wales after gaining new intelligence on the activities of a suspected slave gang. In total more than 100 policemen are investigating the gang, believed to be run by travellers who force their captives to work 12-hour days with no rest and no pay. Body hunt: Police and forensic archaeologists were today hunting for a body buried by slavers Meticulous: Police prepare to hunt for the bodies on a farm in Marshfield, South Wales The search began after police made dawn raids on a series of properties around Newport in which four people were arrested. Three addresses were targeted by police as part of a long--running operation on workers kept in "slave conditions." A 66-year-old man and a woman, 42, both from Marshfield, a Cardiff man, 36, and a woman, 42, from Penhow were taken into custody. An east European man was also taken from the Marshfield address to hospital for assessment of his physical and mental condition. The investigation into the suspected slavery gang began after police found a man who said he escaped from the gang after being enslaved for 13 years. Darrell Simester, 43, from Worcestershire was reunited with his family after he was found living in a filthy caravan in South Wales with no running water. Specialists: The hunt was launched after new intelligence on activities linked to slavery was found Police presence: The hunt for the body was launched after four people were arrested today in a dawn raid He was starving, wearing dirty, torn clothes and had teeth missing. Darrell claimed he had been treated like a slave by his masters - who lured him in by offering him a job. He said he was forced to work 12 hours a day and was never given a day off or allowed to visit a doctor, but he was so scared of punishment that he didn't try to escape. But he told how his fear of repercussions stopped him from running away. Police yesterday said they began investigating whether a slavery gang was operating in South Wales after Darrell's treatment came to light. Escaped: Darrell Simester, left, says he escaped his slave masters, who forced him to work without pay. He is pictured here reunited with (left to right) his brothers Brendan and Duncan and sister Zoe Comprehensive: The hunt is part of a long-running investigation into the suspected slave gang Detective Superintendent Paul Griffiths of Gwent Police said: "Today's action is the latest phase of a long running investigation into alleged offences of Slavery and Servitude. The investigation began when a 43-year-old man was found to be living at the Marshfield site in very poor conditions having been reported missing by his family for 13 years. Since then a specialist team of detectives has been investigating and gathering intelligence to ascertain whether this part of a larger criminal conspiracy. In addition to the suspected offences in relation to Slavery and Servitude, we are also acting on intelligence which suggests that the body of an unknown person may be buried. As such specially trained officers, equipment and a forensic archaeologist have been deployed to investigate this. The offences that are being investigated are extremely serious and we would urge anyone with any information which could assist the team to contact Gwent Police.