© London News Pictures. File pic dated. 13/12/2012. Swansea, UK. A BBC investigation into a UK-based Amazon warehouse has found conditions that a stress expert said could cause "mental and physical illness". PICTURED - Staff at the Amazon Swansea fulfilment centre process orders as they prepare their busiest time of the year. The 800,000 sq ft fulfilment centre, the largest of Amazon's plants in England and Whales, is big enough to hold 10 football pitches. Over 1,000 extra jobs are created at the centre to cope with the extra seasonal workload. Photo credit: Ben Cawthra/LNP