Barbie dolls for sale at a Target store.
Scott Mlyn | CNBC
Mattel had received a subpoena in December from the U.S. Securities and Exchange Commission seeking documents related to a whistleblower letter and subsequent investigation, the U.S. toymaker said in a filing on Tuesday.
In connection with the letter, an independent investigation by Mattel's audit committee and a separate probe by the company's external auditor found that the lead audit partner of the external auditor violated SEC rules.
Mattel had disclosed in August that it received the anonymous letter.