Stalin decimated the Ukrainian citizenry by quarantining and denying food to villages, said Stanislav Kulchytsky, deputy director of the Institute of Ukrainian History in Kiev.
Kulchytsky said he could reach no other conclusion after studying Ukrainian and Russian archives, The New York Times reported Monday.
"The documents about cannibalism are especially difficult to read," he said.
A quarter century ago, Kulchytsky was ordered by Soviet officials to depict the famine as a natural disaster. He refused and released his findings publicly, escaping punishment only because glasnost had begun under Soviet leader Mikhail Gorbachev, the Times reported.
Kulchytsky was present last November in Kiev when Ukraine dedicated a memorial to the victims of the famine. Russian officials, including President Dmitri Medvedev, have accused Ukraine of using the famine to discredit Russia, the Times said.