A US jury has awarded $100m (£62m) in damages to 10 workers who said a leak at a BP oil refinery in Texas in 2007 had made them sick.

The source of the leak at the refinery south of Houston was never identified and environmental agencies reported no evidence linking it to the refinery.

BP concluded that any toxic substance had come from outside.

But lawyers for the workers argued the odour had come from a sulphur recovery unit at the plant.

They described BP as a serial polluter.

The Texas jury agreed with the lawyers’ case and imposed punitive damages.

A hundred workers at the refinery were sent to hospital after being overcome by a toxic substance and a further 90 claims are to come.