An employee of the Tokyo Stock Exchange is under investigation for suspected insider trading. The TSE's parent company, the Japan Exchange Group, says it is fully cooperating with authorities.

Sources say the TSE employee is suspected of providing undisclosed corporate takeover information to family earlier this year. The employee had advance access to company details that firms disclose to investors.

Sources say trades were made based on the information.

Japan's Securities and Exchange Surveillance Commission has opened an investigation. It's looking into possible violations of the Financial Instruments and Exchange Act and has raided some locations associated with the employee.

It was also revealed this month that a judge at the Financial Services Agency was investigated for allegedly trading based on undisclosed corporate information.