Soviet nuclear specialist Valery Legasov, a member of a government commission set up after the Chernobyl disaster, committed suicide, an official at the plant said.
Alexander Kovalenko, information chief of the Kombinat group supervising the Chernobyl cleanup, issued a clarifying statement Thursday on the cause of Legasov's death, which was announced by Soviet television April 29.
Legasov, deputy director of the Kurchatov Atomic Institute and a member of the Soviet Academy of Sciences, died April 27. He was 51.
"We know without reading it in the newspapers that he committed suicide," Kovalenko told a group of scientists and reporters visiting Chernobyl. "To go into details would be impolite."
His remarks came midway through a three-day conference that brought more than 160 Soviet scientists together with delegates from 24 foreign countries.
Soviet scientific sources in Moscow have said that Legasov was in good health but had become increasingly depressed because he felt he was somehow to blame for the accident.
Chernobyl, the world's worst nuclear accident, killed at least 31 people, gave 200 others radiation sickness and spewed a cloud of radiation over much of Europe.