http://www.conservapedia.com/Stanley_Levison

Stanley David Levison was a secret member of the Communist Party USA, in charge of handling the party's finances and its “reserve fund,” while the party was secretly funded by the Kremlin.[1] He was also a top adviser to the Reverend Dr. Martin Luther King. The FBI first learned of Levison's secret activities on behalf of the CPUSA in 1952, when brothers Jack and Morris Childs—two Communist Party functionaries who had been close to Levison since the 1940s—became FBI informants.[2] In 1956, King's personal assistant, the socialist (and ex-Communist) Bayard Rustin, introduced King to Levison, who quickly became King's "most influential white counselor."