[[Image:KasparovKamenKheifitsLarge.gif|right|300px|thumb|Surveillance photograph taken by [[Manhattan Project]] security officials. On the right is Gregory Kheifits, San Fransisco Francisco KGB ''Rezident'', center [[Martin Kamen]], left [[Gregory Kasparov]] (Courtesy National Security Archives). [http://www.cfo.doe.gov/me70/manhattan/kasparovkamenkheifits.htm] ]]'''Grigory Kheifets''', also known as '''Grigori Kheifetz''', was the San Fransisco Francisco [[KGB]] station chief, or ''[[Rezident]]'', from December 1941 until July 1944.<ref>[http://www.nsa.gov/publications/publi00036.pdf ''The Venona Story''], Robert L. Benson, Center for Cryptological History, National Security Agency.</ref>
Kheifetz first contact with [[J. Robert Oppenheimer]] came at a party to raise money for [[Spanish Civil War]] refugees hosted by Kheifetz's mistress, [[Louise Bransten]] on December 6, 1941, the day before Pearl Harbor.<ref>Pavel Sudoplatov, Anatoli Sudoplatov, Jerrold L. Schecter, Leona P. Schecter, ''Special Tasks: The Memoirs of an Unwanted Witness -- A Soviet Spymaster'', Little Brown, Boston (1994), pg. 175.</ref> Kheifetz managed to meet Oppenheimer alone for lunch later in December 1941 where Oppenheimer told Kheifetz about the Einstein-Szilard letter to President [[Franklin Roosevelt]] and provided details on the current status of the US atomic research program.<ref>Jerrold Schecter and Leona Schecter, ''Sacred Secrets: How Soviet Intelligence Operations Changed American History'', Brassey's Inc., Washington, DC, 2002, pgs. 47-49.</ref> Kheifetz advised Moscow by cable from Washington that the outstanding physicists in the Allied world including Nobel Prize winners and giants like [[Albert Einstein]], were involved in a secret project. This changed Moscow's attitude toward about the atomic project.