The domestic spy case of which man increased fears of communist influence within the u. s. government? richard nixon whittaker chambers klaus fuchs alger hiss

Alger Hiss--He was a government official and employee of the state department. 

Alger Hiss was an employee of the State Department in charge of top secret documents and charged with being a Soviet spy. Whittaker Chambers claimed he had evidence Hiss was a spy and an investigation began putting Hiss in prison. During his trial, Hiss stated he was innocent and continued to state that until his death. Hiss was convicted of perjury because he lied about knowing Chambers but it was too late for the government to put him on trial for treason.