AMAZON warehouse staff are peeing in bottles because loos are hundreds of yards away.
One ex-worker said staff fear getting into trouble for taking too long away from the job.
The warehouse measures 700,000 sq ft and some of the 1,200 workers face a ten minute, quarter-of-a-mile walk to two toilets on the ground floor of the four-storey building.
Undercover investigator James Bloodworth said: “For those of us who worked on the top floor, the closest toilets were down four flights of stairs.”
Mr Bloodworth, who worked ten-hour shifts as a picker selecting goods for despatch, walked ten miles a day in the job to research for a book on low-wage Britain.
He claimed workers were continually monitored for time wasting by supervisors.