Federal prosecutors began investigating possible illegal fund-raising by the Nixon re-election campaign in 1973 as part of the Watergate scandal. Cook was called before a grand jury to testify about the Vesco donations on April 19, 1973, and again on May 3 and May 7, 1973. He also testified before a Senate committee on May 1 and May 14, and before a House committee on May 22. During this testimony, Cook swore under oath that he had never discussed the Vesco case with Stans until after the case was filed on November 27, 1972.