Yegor Gaidar, one of the leading architects of free market reforms in post-Soviet Russia, has died at the age of 53, his aide said on Wednesday.
"Yegor Gaidar has died, I cannot currently give any more details," Gennady Volkov said.
Gaidar reportedly died of natural causes when a blood clot became dislodged.
He was one of the young reformers, including Anatoly Chubais and Boris Nemtsov, that President Boris Yeltsin surrounded himself with in the early 1990s and was acting prime minister during the second half of 1992.
The parliament refused to confirm Yeltsin's choice, and Gaidar stepped aside for Viktor Chernomyrdin to become the president's economic adviser.
He was vilified by the public for the hardships caused by his "shock therapy" policy to move Russia from the Soviet planned economy to free-market capitalism and left government in 1994, although he was elected to serve two terms in the State Duma, in 1993-1995 and 1999-2003.
Chubais, the minister responsible for privatization in the early 1990s, praised Gaidar as Russia's savior.
"It was Russia's huge good fortune that in one of the worst moments in its history it had Yegor Gaidar. In the early 1990s he saved the country from famine, civil war and disintegration," Chubais wrote in his blog.
Chubais, who was also demonized over the economic reforms of the 1990s but unlike Gaidar has remained near the center of Russian power, said the former top official had remained an "intellectual and moral leader for all of us."
"Few people in the history of Russia and in world history can be compared with him for force of intellect, clarity of understanding of the past, present and future, and a willingness to take the most difficult but necessary decisions," wrote Chubais, who oversaw the breakup of electricity monopoly UES and now heads the Russian Nanotechnology Corporation.
Ian Bremmer, the president of Eurasia Group, one of the leading experts on Russia, told RIA Novosti, "I'm very sad to wake and learn of this news. It makes you realize how far we are from the days of 'transition'. egor was a towering intellect, a global thinker whose conception of Russia was grounded in history but not incapacitated by it. His untimely passing comes as a shock. This time, there's even less therapy. I'll miss him."
Gaidar was born March 19, 1956 in Moscow, the son of former Navy admiral and journalist Timur Gaidar and grandson of famous writer Arkady Gaidar.
He is survived by his wife, three sons and daughter.
MOSCOW, December 16 (RIA Novosti)
Yegor Gaidar 
Russian liberal economist and politician Yegor Gaidar died on Wednesday at the age of 53. He was the son of the famous Russian journalist Timur Gaidar.

Born in Moscow in 1956, he graduated in economics from Moscow State University in 1978. In January 1992 in the position of Russia's first finance minister he dropped state control over prices, making Russia a capitalist country with a market economy. While working as an acting Prime Minister of Russia, Gaidar provided the so-called "shock therapy" treatment of the Russian economy, a set of liberal economic reforms.

His health was declining after he was allegedly poisoned in Ireland in 2006, collapsing soon after eating breakfast. This episode led to comparisons to Alexander Litvenenko, killed with radioactive polonium in November 2006.

Yegor Gaidar died of a blood clot at his home in the Moscow region. He is survived by his wife, three sons and daughter. His funeral is scheduled to take place on Saturday, the burial place is yet to be decided.