The Soviet Union has formed another commission to determine whether thousands of people found in a mass grave outside this Ukrainian village were killed by the Nazis or Josef Stalin's secret police.

Three previous Soviet investigations have blamed German forces who occupied the area from 1941-43, but elderly residents of this village near Kiev recently broke 50 years of silence on the matter. They blamed their government for the bodies - up to 300,000 by one unofficial estimate - buried in the forest.One witness, Petro Z. Kukovenko, says he summoned the courage to speak after a Soviet commission reburied the bones and erected a memorial in May blaming the Nazis for the killing.

"When they put up this monument, I became ashamed that they were blaming this on the wrong people," said Kukovenko, 74.

"My father may be buried there," said Kukovenko's wife, Halyna. "My father was a collective farmer, and they killed him for nothing," she sobbed.

Western historians estimate 20 million Soviets were killed under Stalin, particularly during the Great Purge of the late 1930s.

But it was only in 1987 that the Soviet government, as part of the reforms instituted under President Mikhail S. Gorbachev, began to admit that Stalin was responsible for even thousands of deaths.

Mikola G. Lysenko, a retired economist, is crusading to end what he considers a conspiracy of lies. In December, he succeeded in forcing the government to form a fourth commission to find the killers.

Lysenko said that 50 villagers say the bodies were killed before the German occupation.

All four commissions have involved officials with connections to the secret police, Lysenko said.

Kukovenko lived through that terrible time from 1936 to 1941, when canvas-covered trucks hauled their mysterious cargo to the green-fenced compound in the Darnitsia Forest.

He first saw the horror when a German officer forced him and four other men to exhume one of the graves just four days after Nazi troops occupied the area in September 1941.

Government estimates range from 6,000 to 68,000 bodies, but Lysenko said there are five to eight victims in every 2 square yards of the 80,000-square-yard site. That amounts to 200,000 to 300,000 people.