A unit of Japan's Panasonic Corp. is under investigation by U.S. authorities looking at whether the company paid bribes overseas to airline employees or government officials to help land business, the Wall Street Journal reported.

Citing company documents, the Journal said Panasonic Avionics had received a subpoena looking for communications between Panasonic Avionics, consultants and others. The subpoena also asked for documents related to payments to the airline employees and government officials, the newspaper said.

The Panasonic unit, which is headquartered in Lake Forest, California, makes in-flight entertainment and communications systems.

According to the Journal, notices were sent to executives and employees in Asia, Europe and the Middle East.

The Journal said it was not clear which U.S. agency is investigating the unit. But the U.S. Foreign Corrupt Practices Act is enforced by the U.S. Department of Justice and the Securities and Exchange Commission.

A Panasonic Avionics spokesman told Reuters that the company does not comment on government investigations.

The SEC and the Justice Department could not immediately be reached for comment.