Three Florida fruit-pickers, held captive and brutalised by their employer for more than a year, finally broke free of their bonds by punching their way through the ventilator hatch of the van in which they were imprisoned. Once outside, they dashed for freedom.

When they found sanctuary one recent Sunday morning, all bore the marks of heavy beatings to the head and body. One of the pickers had a nasty, untreated knife wound on his arm. Police would learn later that another man had his hands chained behind his back every night to prevent him escaping, leaving his wrists swollen.

The migrants were not only forced to work in sub-human conditions but mistreated and forced into debt. They were locked up at night and had to pay for sub-standard food. If they took a shower with a garden hose or bucket, it cost them $5.

Their story of slavery and abuse in the fruit fields of sub-tropical Florida threatens to lift the lid on some appalling human rights abuses in America today.

Between December and May, Florida produces virtually the entire US crop of field-grown fresh tomatoes. Fruit picked here in the winter months ends up on the shelves of supermarkets and is also served in the country's top restaurants and in tens of thousands of fast-food outlets.