Michael Clemente's career as an official of the International Longshoremen's Union and a Genovese family mobster dates to the 1950s. In December 1952 Clemente and Cosmo "Gus" Frasca were arrested for extorting $2,500 from the John W. McGrath Company, a stevedore firm. The extortion had occurred between July and December 1952. In February 1981 Clemente was involved in an FBI inquiry that resulted in 110 convictions. Clemente was heard in conversations between himself and New York businessman, turned informant, William "Sonny" Montella.