In 2006, the U. S. Securities and Exchange Commission (SEC) began investigating the conduct of UnitedHealth Group's management and directors, for backdating of stock options. Investigations were also begun by the Internal Revenue Service and prosecutors in the U. S. attorney's office for the Southern District of New York, who subpoenaed documents from the company. The investigations came to light after a series of probing stories in the Wall Street Journal in May 2006, discussing apparent backdating of hundreds of millions of dollars' worth of stock options by UHC management. The backdating apparently occurred with the knowledge and approval of the directors, according to the Journal. Major shareholders have filed lawsuits accusing former New Jersey governor Thomas Kean and UHC's other directors of failing in their fiduciary duty. On October 15, 2006, CEO William W. McGuire was forced to resign, and relinquish hundreds of millions of dollars in stock options. On December 6, 2007, the SEC announced a settlement under which McGuire will repay $468 million, as a partial settlement of the backdating prosecution.