BUNGLING workers have flushed £500,000 of whisky down the drain in a cleaning blunder.

Staff at the Chivas Brothers bottling plant in Dumbarton were left red-faced after the error resulted in 18,000 litres of Scotch pouring into local sewage works.

The mistake occurred during a routine cleaning shift in the early hours of Tuesday morning at the plant, which employs around 600 workers.

It is understood there was some confusion and instead of water and cleaning fluid being drained from machinery, the whisky was released instead.

A source at the factory said: "It happened on a nightshift wash-out – that's when the equipment is cleaned for a change-over between different products.

"Instead of draining the water and cleaning solution, they flushed out all the whisky.

"It was like someone turned on a tap and it just ran straight down the plughole. What's even more shocking is that no-one noticed until 11am."

They said bosses at the plant were "livid", adding: "The guys responsible will be lucky to keep their jobs."

A spokesman for Chivas Brothers said a probe was under way.