British police were on Tuesday hunting for human remains as part of an investigation into alleged slavery at several sites in Wales.
More than 100 officers have searched a string of properties in south Wales after a man was found living in harrowing conditions at a farm in the village of Marshfield, near the city of Newport, 13 years after his family reported him missing.
Darrell Simester had torn clothes and missing teeth when he was found by police last March at the farm, which is described by the local council as occupied by gypsies and travellers.
Four people were arrested Monday by police investigating the alleged slavery, in a case the interior ministry described as "shocking".
"It is an appalling reminder of the extent to which slavery has reappeared in our country," a ministry spokesman said.
A second "vulnerable" man, believed to be from eastern Europe, was discovered on Monday. His mental and physical health were being examined by Red Cross officials.
Meanwhile forensic teams were combing the Marshfield farm after police received evidence that a person may have been buried there.
Several other addresses in south Wales were raided on Monday over claims that people have been kept in poor conditions and forced to work for no pay.
"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 at the Marshfield site," said Detective Superintendent Paul Griffiths of Gwent Police.