The firm, Third Point, which owns about 5 percent of Yahoo!, revealed last week it discovered Thompson's online biographies listed him as earning a degree in computer science from Stonehill College in Massachusetts. The college did not offer a degree in computer science at the time Thompson was a student there, Third Point said.
Yahoo! then admitted it had made a mistake listing the CEO's credentials, The New York Times reported Monday.
The issue escalated as Yahoo! admitted board member Patti Hart, the lead executive involved in hiring Thompson, also had misstated her academic record in her official biographies.
Thompson, a former executive at eBay, earned an accounting degree from Stonehill, which also has been listed on his official credentials.
Third Point, which has been attempting to install its founder, Daniel Loeb, and others on the Yahoo! board, has also requested information about other board member candidates.
Third Point is asking for the information under a Delaware provision known as a "books and records" request.
"Third Point believes that Yahoo shareholders and employees will be best served if the board accepts responsibility quickly for this latest debacle. If the directors are truly interested in 'working in a constructive manner with Third Point,' they should provide answers promptly," the hedge fund said in a release.