Three managers at the Lennoxtown plant have been sacked
An internal audit at Scottish mineral water company Campsie Spring has uncovered a £15m fraud.
Campsie's parent company, Greencore, said the loss had been incurred through a deliberate concealment of costs rather than embezzlement.
It said the fraud was committed by a former financial controller who left before the problem was discovered.
Three managers at Campsie, who had supervisory roles over the controller, have since left the company.
A new managing director and financial director have been appointed at Campsie Spring's headquarters in Lennoxtown, East Dunbartonshire.
A statement on the Greencore website said concerns about the accounts emerged after an internal audit on 6 June.
A full investigation was launched three days later and a report identifying the concealment issues was presented to the board on 20 June.
The accounts of Greencore have been severely hit by the fraud.
It is understood overall operating profit in this financial year will be reduced by more than £7m.
The company will also have to restate its accounts to reduce profits by more than £6m in 2007 and more than £3m in 2006.
Greencore said it was taking legal advice on whether any of the cash could be recovered.
It is now conducting "a thorough review" of all its internal control, financial reporting and external audit processes.
Greencore bought the Campsie Spring in 2001.