A Russian government commission found that Anatoly Chubais, the former head of the national power monopoly, was among those responsible for the Siberian hydropower station accident that killed 75 people in August, Reuters repored.
Prime Minister Vladimir Putin had ordered the investigation into the accident and said it was "irresponsible and criminal" to compromise on safety at the plant, but it was not immediately clear whether Chubais would face any charges.
The report issued on Saturday said that Chubais and five other officials were responsible for "creating the conditions that contributed to the accident."
Chubais' spokesman could not be reached for comment, and no one was available for comment at Russia's state nanotechnology corporation, the body he now heads.
Chubais led the effort to break up the UES monopoly by privatizing and spinning off its electricity production assets into separate companies.
He was a key adviser to former President Boris Yeltsin and remains widely unpopular in Russia for his hand in the economic policies of the 1990s that led to the rise of the oligarchs.
The August 17 accident at RusHydro's 31-year-old Sayano-Shushenskaya dam led to calls for increased safety measures at Russia's Soviet-era utilities.
Putin proposed installing monitoring systems similar to the "black boxes" used on airplanes to monitor power stations across the nation.
At a news conference on Saturday, Nikolai Kutyin, who heads the Rostekhnadzor industrial safety watchdog, said a range of factors were responsible for the accident, which occurred when a turbine room flooded at the Sayano-Shushenskaya dam.
"A number of underlying conditions that preceded the accident caused the destruction of the second hydroelectric generator," Kutyin said.
MAINTENANCE
He said one of these was poor maintenance, which caused the second turbine to vibrate excessively and then explode when it was forced to generate more power in order to make up for a shortfall caused by a fire at a separate power plant in Siberia's Bratsk.
Among the others the report blames for the accident are former Russian Energy Minister Igor Yusufov, as well as a former head of the TGK-1 utility and the former director for technical matters at UES.
The total cost of the repair work is expected to reach at least 40 billion roubles ($1.3 billion), and Energy Minister Sergei Shmatko said on Saturday that RusHydro would earmark 5.6 billion roubles for repairs this year and 16 billion roubles next year.
Sayano-Shushenskaya is RusHydro's largest power plant, with an installed capacity of 6,400 MW, roughly one quarter of the company's total.
It was completely shut down after the accident, and is not expected to return to full capacity until 2014.