Airport services operator Alpha Airports is to prosecute an unnamed UK-based subcontractor which the company claims has defrauded it out of #2.5 million.
Alpha revealed in January that it may have been the victim of a fraud by a third party, which it declined to name.
Yesterday, along with full year results, it said further investigation indicated the group has lost up to #2.5 million in a fraud across several European countries.
Chief executive Kevin Abbott said: "This is a one-off process that we sub-contracted to them and we think they've run off with our money."
He said Alpha has decided to prosecute the company itself before handing over information to the police and the Crown Prosecution Service.
"We are prosecuting because we want to get to the top of the queue in terms of any asset recovery because we believe we won't be the only company who has been subject to this fraud," he added.
The development took some of the shine off Alpha's results, which showed a 6.3 per cent rise in profit before tax, exceptional items and impairment costs to #18.5 million for the year to January 31.
Sales rose 12.9 per cent, from #487.8 million to #550.9 million, while earnings per share increased by 51.8 per cent, from 3.78p to 5.74p.
The final dividend payment rises 6.6 per cent, from 3p to 3.2p per share.
Alpha, which yesterday officially opened its new 12,000 sq metre tax and duty free store at Birmingham International Airport - part of the first phase of a #2.5 million investment - said the year had seen "ongoing progress" for the group
Chairman Graham Frost said that over the last few months the company had conducted a thorough review of its operations. In the UK, the business is being restructured into two divisions, Alpha Airline Services and Alpha Airport Services.
"This reorganisation will enable us to reduce costs, leverage synergies between the airport and airline businesses and improve our capacity to lead consolidation in the market."