In-flight caterer Alpha Airports is planning legal action over claims it was defrauded out of £2.5m.
A lawsuit is likely to follow an internal Alpha probe, which investigated the handling of overseas VAT payments in several European countries by a UK-based third party.
Sources close to Alpha allege cash was siphoned off over a period of time and in January the company notified the City of its concern that it had been a victim of fraud.
Caterer was unable to contact those at the heart of the inquiry and it is understood they have yet to be tracked down by Alpha.
Alpha was alerted when the countries in question, which are thought to include Germany, Holland, Romania and Bulgaria, demanded the VAT payments.
A spokesman for the company admitted legal action was pending and refused to deny the story was false.
Willie Seeman, founder-president of the International Travel Catering Association, said companies should always be careful when entrusting the handling of overseas VAT payments to third parties.
"It isn't the most prudent way of doing business or controlling your funds," he said.
In April this year Alpha's shares were pulled from the London Stock Exchange when accountancy firm PricewaterhouseCoopers refused to sign off its accounts owing to legal uncertainties surrounding a deal with Icelandic charter airline group Excel Airways.
As part of this separate investigation, the company's former chief executive, Kevin Abbott, and finance director, Heather McRae, resigned suddenly in May.
An Alpha spokesman said the company's shares should be relisted on the London Stock Exchange within the next two to three weeks once the situation had been resolved.
By Tom Bill