A group of Israeli scientists claimed to have solved the mystery surrounding the death of communism's greatest icon V I Lenin, who they said actually died of syphilis.
The revolutionary leader was officially said to have died of arteriosclerosis - thickening, hardening and loss of elasticity of the arterial walls resulting in impaired blood circulation, but rumours had always persisted over the ensuing years that it was a cover up.
After five years of intense research, the Israeli team claims to have convincing proof in support of their submission that Lenin died of syphilis 80 years ago.
Writing in the European Journal of Neurology, three doctors from Ben-Gurion University in Jerusalem, said they used medical records released after the fall of Soviet Union to reconstruct the Soviet leader's illness and death.
The team said that syphilis caused Lenin brain damage and later dementia in the last two years of his life.
The researchers relied on the medical charts, results of a post mortem examination and memoirs of physicians who treated Lenin.
Officially, Lenin died of arteriosclerosis, but only eight of 27 doctors who treated him were willing to put their names to the death certificate. Among those who refused to sign were his two personal doctors, they said.
"For many years, I had read about Lenin's deterioration in his last three years and the symptoms that were described did not match the medical definition of his official cause of death - arteriosclerosis," Dr Eliezer Witztum of Ben Gurion University, who was one among the three researchers told Israel21c, the website of a NGO in Israel.
According to him, the diagnosis of syphilis was particularly problematic in the 19th and early 20th century as the disease often mimics other brain disorders.
However, the discovery that a committee of Soviet doctors prescribed the medicine, Salvarsan, an arsenic-based treatment that is used only to treat syphilis, was a strong indication that his doctors knew the true nature of his disease.
Citing yet another strong proof in support of their finding, Witztum said, "My colleague at Ben-Gurion University, Professor Vladimir Lerner, worked as a psychiatrist in Moscow with the son of Lenin's chief physician who confided that among the many autopsy reports at the time of Lenin's death was one which cited the cause of the death as syphilis."
Our work was primarily in psychobiography - the biography made out employing psychological theory and research whose typical focus is an individual of historical importance, he said.
"We combined forces along with Dr Yoram Finkelstein, Head of diagnostic neurology at Jerusalem's Shaare Zedek Hospital. With his expertise in toxology and neurology, we had all sides covered," he added.
The researcher said that the blood test results were deliberately missing from his medical chart while the results of far less accurate urine and lumbar puncture tests are still in the file.
According to the researchers, Lenin's crippling neuro-syphilis caused massive brain damage and dementia in the last two years of his life and had an impact on ensuing events in his country.
"His private business affected the lives of millions because of his illness, his inability to lead the country at a crucial time," said Finkelstein.
"In 1923, Stalin was able to take control of his party. If Lenin's condition had been public, that would never have happened," Witztum is quoted to have told Israel21c.Lenin's body is still on display in a specially constructed mausoleum in Moscow. His preserved brain might furnish the final proof but the doctors doubt Russian officials would ever allow independent scholars to study tissue samples.