MANILA - A GAS leak at a Petron Corp. oil refinery in the Philippines killed one person and left another in critical condition in hospital, police said on Monday.

A company spokesman said the 'localised accident' occurred at the Petron refinery in the Bataan peninsula at the mouth of Manila Bay, during which the workers were exposed to hydrogen sulphide.

A technician found the two victims unconsconscious at the facility at dawn.

Both were taken to hospital but one of them, an operations technician, was pronounced dead, said Bataan police chief Manuel Gaerlan.

The second victim, a chemical engineer, remains in 'critical condition', Senior Superintendent Gaerlan said in a written report.

Hydrogen sulphide is a highly toxic substance that is a by-product of oil and gas production. -- AFP