WASHINGTON -- President Bill Clinton and Hillary Rodham Clinton have been questioned under oath about events surrounding the death of presidential aide Vincent Foster and other matters related to the Whitewater affair, according to the White House. The Clintons, who have been battered politically over business and ethical dealings in their past, were interviewed separately at the White House on Sunday afternoon, White House counsel Lloyd Cutler said. "As the president previously announced, he and Mrs Clinton are cooperating fully with the independent counsel and voluntarily agreed when the interviews were requested," Cutler said in a written statement. He said the subjects were "events surrounding the death of Vincent Foster," a top White House aid and old Clinton friend from Arkansas who police say committed suicide last summer, and "communications between the Treasury and White House staffs" concerning a government probe of Whitewater matters. Fiske is investigating the ethics and propriety of the Clintons' investments in an Arkansas land deal known as Whitewater in the late 1970s and early 1980s, plus related matters including the failure of an Arkansas savings bank owned by a Whitewater partner. Foster's death is relevant because he had overseen Clinton staff handling the controversy and Whitewater documents were found in his White House office after his death. The Clintons have repeatedly protested their innocence, and no charges are pending against them.