Intel, the world's biggest computer chipmaker, has been raided by European Union competition regulators amid claims it abused its market position.
Intel could face a large fine
Chuck Mulloy, a spokesman for Intel, said the regulators raided the company's office in Munich, Germany.
Mr Mulloy said Intel was co-operating with the investigators.
Intel has been accused of trying to abuse its dominant market position by selling its products below cost price and making cash payments to customers.
"I can confirm that there has been a raid on our offices in Munich," Mr Mulloy said.
"As is our normal practice, we are co-operating with authorities," he added.
The European Commission has yet to name Intel, but confirmed that officials had carried out "unannounced inspections" at the premises of a chipmaker.
Commission spokesman Jonathan Todd said it had reason to believe the firm in question had violated European laws on restrictive business practices.
A number of Intel's main suppliers have also had their offices visited by inspectors.
UK retailer DSG International, which owns PC World and Currys, said Commission officials had visited its offices in Hertfordshire.
"We are fully cooperating with the inspection," said a DSG spokesman.
The investigation started after a complaint from Intel's smaller rival AMD.
The initial findings of a probe by the Commission unveiled last summer concluded that the chip firm engaged in anti-competitive action to thwart AMD.
It accused the world's largest chipmaker of giving rebates to customers provided they bought Intel products and offering incentives to companies to delay or cancel products containing AMD technology.
Intel faces a closed hearing in Brussels on 11 and 12 March on the charges.
European regulators have the power to fine Intel up to 10% of annual turnover if they find it guilty of stifling competition.
Intel has said it is "confident" it had acted lawfully.