Three workers who fell ill after drinking water from a cooler on a jobsite at Ramco Industries Limited have been released from hospital. And one of them has already returned to work, general manager Hamish Fraser said yesterday.

Fraser said since the incident happened two weeks ago, workers have been drinking bottled water while on duty.

"Until we are certain as to what caused the workers to fall ill we have stopped all coolers and are providing them with bottled water," he said.

Fraser said samples were taken from the cooler and results are expected next week.

"But as for the forensic tests which were being done by the police, I cannot say when we would get the results," he said.

The three workers were treated at the San Fernando General Hospital for what was described as "severe poisoning".

Christopher Skeete, 25, and Ako Ayres, 22, are still recovering at their homes, while Daniel Harewood has returned to work, Fraser said.

"We have been in contact with the other two workers and they are recovering well. They are out of danger," he said.

An investigator at the San Fernando CID was unable to say when they would receive the results on the samples taken from the cooler.