It was a tragic tale of forced labour and a ruthless gangmaster.Two years ago 21 illegal immigrants who were collecting cockles and other shell-fish off England’s north-west coast were cut off by the tide and drowned. They had been forced to stay on the treacherous Morcambe Bay sands long after it was safe. But yesterday police successfully prosecuted the man responsible.Mick Gradwell of Lancashire Constabulary gave a statement after the trial. “I always think at a time like this, it can never replace their loved ones, but I hope that they see that we care and that the Criminal Justice System has worked and I hope that it gives them as much a crumb of comfort as it possibly can.” Lin Liang Ren, originally from China, was found guilty of 21 counts of manslaughter.He employed up to 70 Chinese illegal immigrants, housing them in several properties in Liverpool. He paid them the minimum and failed to inform them of the dangers involved in working the beaches. On the night in question police said the victims found themselves in a horrendous situation, cut off from safety and many unable to swim. Those who died were aged between 18 and 45. The bodies of two of them have never been recovered.