LONDON — Britain’s Serious Fraud Office is looking into allegations that a unit of European Aeronautic Defense & Space bribed Saudi Arabian officials to win a multibillion-dollar contract, a person with direct knowledge of the investigation said Tuesday.

The fraud office, which investigates complex instances of corruption, is seeking more information about allegations that the EADS unit handed out cars, jewelry and cash to win a £2 billion, or $3.3 billion, contract for upgrading the satellite systems of the Saudi National Guard, said the person, who declined to be identified because the investigation was at an early stage.

The allegations were made by Lt. Col. Ian Foxley, a former employee of GPT Special Project Management, which won the contract, The Daily Telegraph newspaper reported. GPT, based in Riyadh, is owned by a British company, Paradigm Services, which in turn is owned by EADS, one of Europe’s largest military contractors and the parent company of Airbus.

“Certain allegations have been made and these are being properly investigated,” said Alexander Reinhardt, an EADS spokesman. Sam Jaffa, a spokesman for the fraud office, declined to comment. Mr. Foxley could not be reached for comment. There was no answer at the press office at the Saudi Embassy in London.