He was a reporter for the "Paris-Match" magazine and after traveling extensively as a foreign correspondent, he became its New York Bureau chief for 20 years until 1978.
He also worked for Radio Free Europe, was a contributor to the Bulgarian Service of BBC and was active in a few emigre organizations and publications in exile.
He was the first Bulgarian to visit Antarctica as a journalist and to have set foot on the South Pole; after Mario Anton Weller, MS-a Bulgarian American- who went to the Antarctic in 1971–1972 as chief of the expedition that installed there a satellite tracking station and antenna for the European Space Research Organization whose DG was Hermann Bondi (the project was led by Umberto Montalenti director of ESA's Operation Center).
As a historian of the construction of the first atomic bomb, he was invited as a speaker at the 60th commemoration of the Manhattan Project in Washington D.C. and in Oak Ridge, Tennessee.
Groueff is the author of eight non-fiction books in French and English, three of which, Manhattan Project: The Untold Story of the Making of the Atomic Bomb,[2][3] Crown of Thorns,[4] and My Odyssey[5] were translated in Bulgarian.