Amazon Japan said on Thursday it had been raided by the Japan Fair Trade Commission on suspicion of possible anti-trust violation.

Citing sources related to the matter, Kyodo news agency said the online retailer is suspected of possibly asking suppliers to shoulder part of the cost incurred from selling their products at a discount on Amazon Japan.

The Japan Fair Trade Commission did not immediately comment on the case.

Amazon Japan said it was cooperating fully with regulators, declining to elaborate.