Ahead of them stretched miles of sand and mud, a few remaining hours of daylight and a long, laborious shift searching for cockles. If they knew that by 8.30pm the tide would be lapping at their feet and surging powerfully through the criss-cross of gullies behind them, they showed no sign of it.

They were, it seems, being sent out in treacherous conditions unaware of the danger. By morning, 19 would be dead.

??They were ill-equipped to go on the beach and they went at the wrong time,?? said Detective Superintendent Mick Gradwell, who is leading the investigation into their deaths. ??Nineteen people dying is a tragedy and a tragedy of that proportion has to lead to criminal charges.??

This weekend the target of police inquiries are the ??gangmasters?? who ruthlessly exploit immigrant labourers for tasks such as cockle-picking.

Morecambe Bay is strewn with the shellfish and attracts fishermen from around the country. It is a trade worth ??6m a year, and the combination of free pickings and cheap labour have increasingly been exploited by gangmasters.

Local fishermen who spotted the Chinese group on Thursday afternoon did not consider them out of the ordinary. Such groups have become a common sight in recent months.

When the local fishermen headed for home as dusk fell, the Chinese gang kept on working. Perhaps they were foolish, more likely they felt they had no choice: they were being paid just ??1 each for a nine-hour shift.

As the tide flooded in, the group was more than a mile from the shore. Steve Manning, 49, a fisherman from Flookburgh in Morecambe Bay, said: ??They must have known the time because I later saw some of their bodies and they had watches on.

??They just didn??t realise the danger they were in. They were facing an absolute disaster.

It??s not like a normal tide in that bay. It floods in from the Irish Sea and follows the path of least resistance through the gullies behind you.

??When you get out there, you need to mark your track to get back. And you never go out there without knowing the time of high tide.??

Morecambe Bay is the second largest bay in Britain after the Wash, covering 120 square miles. When the tide comes in, sea-water courses at up to 10mph through the network of gullies and inlets that thread across the bay.

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