The blast caused damage worth billions of roubles
Russian experts warned two years ago that the hydro-electric plant hit by a deadly explosion last month was "85% obsolete", a top official says.
Sergei Stepashin, the head of Russia's Accounting Chamber, says most of the equipment at the Sayano-Shushenskaya dam was worn out.
More than 70 people were killed following the explosion.
He echoed fears that industrial accidents could become more common as Russia's infrastructure ages.
"The station was checked by the chamber in 2007, and we revealed that 85% of the equipment was obsolete," says Mr Stepashin.
"We then made the appropriate approaches to the government and the prosecutor general's office," he adds.
"The replies we received stated that the station was a shareholding business, so let the shareholders pay for the repairs," insists Mr Stepashin.
The Accounting Chamber is the highest official body tasked with performing technical and financial audits.
A representative from RusGidro, the owner of the station, insisted that all necessary measures had been carried out to rectify the problems identified, and that a note to this effect had been sent to the Accounting Chamber.
At the same time, the head of the investigative department of the prosecutor general's office has ordered checks to see whether the management of the station behaved correctly at the time of the accident.
Prosecutors have already opened a criminal case in connection with the accident, based on alleged violation of article 143 of Russia's criminal law - "violation of labour safety rules".
Sergei Stepashin said the warnings were not heeded
Three turbines were completely destroyed in the accident. The remaining seven were seriously damaged.
The Russian Emergencies Minister Sergei Shoigu said repairing the turbine hall alone could cost 40bn roubles ($1.3bn; £762m).
Earlier this week, the first 25 families of the killed and missing received one million roubles (£19,000) in compensation from the Russian government's reserve fund. The other families have been promised theirs soon, and RusGidro has promised each family a further million roubles. The victims' families are demanding five million roubles for each death and 300,000 roubles for each seriously injured worker.
Russia's Ministry for Emergency Situations predicts high, and sometimes growing, numbers of deaths due to fires, gas explosions, building collapses and so on, due to "a high degree of technical obsolescence".
Russia has invested billions of dollars in prestige national projects, but the results are often poor, say analysts.