 In 1981, while on an official visit to Brussels, Nguza fled into exile, where he attempted to unite the exiled Zairean opposition and testified against Mobutu in front of U.S. Congress hearings, outlining, in graphic detail, Mobutu's theft of hundreds of millions of dollars from the country's treasury and its subsequent deposit in foreign banks.Nguza published "Mobutu ou l'Incarnation du Mal Zairois", which was highly critical of the regime.Even so, Mobutu forgave him, invited him back home, and appointed him as ambassador to Washington in 1986.