An anti-slavery patrol freed more than 1,000 workers from a sugar cane plantation hidden in the Amazon rainforest, in Brazil’s biggest rescue operation of bonded labourers.

Officials from Brazil’s Labour Ministry and federal police officers found the workers living in sub-human conditions about 250 kilometres (160 miles) from the jungle city of Belém, where they cut sugar cane to produce ethanol.

The workers were living in crowded accommodation without bathrooms or drinkable water. They were found working back-breaking 13-hour days cutting cane.

Once the company they worked for had deducted “debts” that it claimed the workers owed, they were being paid £2.50 a month. Some said that they received nothing at all. “We found many people sick with diarrhoea and nausea because of the rotten food and bad water,” said Humberto Célio, the official in charge of the operation. Officials are calculating what the company owes the workers in back pay.

The firm involved, Pagrisa, is the only manufacturer of ethanol in the state of Belém, and is a supplier to the state-owned energy giant Petrobras, which is aggressively promoting the sale of ethanol internationally as a clean substitute for petrol. Petrobras said that it would immediately suspend all purchases of ethanol from Pagrisa after the raid.

Most of the workers freed came from the poor neighbouring state of Maranhão. They said that the company recruited them six months ago promising work and paid for their transport to the plantation. But once they arrived, they had to pay for their transport and other supplies.

Pagrisa has vigorously denied that its workers were being held in slave-like conditions. It says that their food and water were supplied by well-known contractors and the crowded accommodation was temporary.

The federal Government has stepped up efforts to combat slave labour in Brazil. About 160 hidden plantations where workers live in slave-like conditions have been found in recent years. Last month it launched a campaign against the practice, which includes pressuring ethanol manufactures to ensure that the small cane suppliers they rely on do not use slave labour or force workers to endure degrading conditions.

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