Airline caterer Alpha Airports is investigating a fraud that it believes could have cost the company up to £2.5m.
In a trading statement it said: "It may result in a significant exceptional loss to the group. Initial investigations show the potential loss is in the order of £700,000 but it could be as high as £2.5m."
The company refused to give any further details on the nature of the crime.
In its statement, Alpha said that a poor first half, which saw profits fall 42% to £6.2m, was offset by a stronger second period in 2005.
It estimates that pre-tax profit for the year will be slightly above last year's £17.4m.
Group turnover is expected to be 12% ahead of last year's £497.2m.
By Tom Bill