LONDON—A massive spill at a Chivas plant has sent the smell of spirits flowing through a Scottish sewer and sorrow coursing through the hearts of Scotch whisky fans.

Chivas Brothers Ltd. spokeswoman Jennifer Stevenson says the group is investigating what she described as an “accidental loss” of spirit at the company’s bottling plant in Dumbarton, Scotland on Feb. 26.

She declined to estimate how much of the bulk whisky had been lost, saying only that it was less than the 18,000 litres (4,755 gallons) mentioned in media reports.

Bulk whisky can be used in various ways, and it wasn’t immediately clear which Chivas brand the liquid was meant to fill.

Stevenson said Friday she did not want to comment on the spill’s circumstances until the company had completed its investigation.