"We were treated like human waste. We were all nameless, just known as guinea pigs," he said.

In his palsied hands he holds an allegorical painting, a white dove - the fragile symbol of peace - is dying, tangled on a strand of barbed wire,as the ominous giant mushroom of a nuclear explosion rises against the skyline.

He says his pictures, stored in a squat house in this bleak town in northeastern Kazakhstan, are a message to posterity.

One features stone-faced Soviet dictator Josef Stalin, dispassionately looking past a heap of human skulls while a nuclear mushroom looms nearby.

Another depicts a mother in Kazakh national dress, sitting in the middle of a vast steppe overcast by a huge nuclear cloud. She is breastfeeding an emaciated child with protruding ribs, a disproportionately large head, and horror in his wide eyes.

"The child is the spitting image of a sick boy abandoned by his parents whom I once saw in an orphanage here," Shevchenko said softly. "He later died."

"I am pressed for time to accomplish all my plans," said the painter, who has not yet fully recovered from his fifth heart attack. "The truth must be told."

CRIPPLED LIFE

The story of Shevchenko, an ethnic Ukrainian from southern Russia, resembles that of many who, against their will, found themselves on the Semipalatinsk test site at the wrong time.

In October 1947, he was brought to this god-forsaken spot in the endless Kazakh steppe as a private in the Red Army to take part in secret work ahead of the first blast on August 29, 1949.

The young man had no choice: before his mission he had been sentenced to eight years hard labour. His crime - living on territory which was occupied by the Nazis during World War Two.

Shevchenko, labelled "an enemy of the people", was just one of thousands to be crippled during Stalinism's uncompromising nuclear race with the United States.

"We had no safety gear and were completely exposed to this deadly radiation. The trenches we dug were our only protection," said the old soldier who served at the test site until 1951.

"When a nuclear bomb explodes, you can see through the body in front of you. All his guts and bones are visible, like in an X-ray," said Shevchenko, who after one such test in 1950 lost consciousness and was treated for leukaemia.

By the time of its 1989 closure, following growing popular protests which even the Soviet leadership could no longer ignore, Semipalatinsk had held 30 surface, 88 atmospheric and 340 underground tests.

The 1949 explosion, which established nuclear parity with the United States, was given ecstatic coverage by the Soviet propaganda machine.

Subsequent nuclear tests were routinely kept secret or, later on, tersely reported on by compliant media as a "forced measure to strengthen the nuclear shield of the Motherland".

There is no precise information on how many people died as a result of these experiments on live people, but some blood-curdling details are becoming available.

HUMANS OR CATTLE?

Boris Gusev, now 64, knows more than most.

In 1961, as a newly qualified doctor, he signed strictly confidential papers with the feared KGB secret police, vowing to keep silent on his future work at the top-secret Dispensary Number Four, set up in Semipalatinsk in 1957.

The nondescript building officially housed a team of doctors dealing with brucellosis, a widespread contagious disease usually affecting sheep and cattle.

In fact, this was a myth invented by the KGB to conceal the real task of the secret laboratory - studying the impact of radiation on human health.