Intel has confirmed that officials from Japan's Fair Trade Commission visited the company's offices in Tsukuba yesterday, but would not give further details.
The FTC is a state body whose remit includes enforcing the Antimonopoly Act, a law designed to remove obstacles to free and fair competition in the Japanese market.
Around 300 people are employed at Intel's Tsukuba office, which is 40 miles from Tokyo. The office handles materials operations, quality assurance, information technology and e-business operations.
Intel is the second US company to have its Japanese offices visited by the FTC in recent months.
In February, FTC officials visited the Japanese offices of Microsoft as part of an investigation regarding provisions in Microsoft licences with PC manufacturers.
Sumner Lemon writes for IDG News Service