SOCHI, Russia -- Russian President Vladimir Putin has warned officials and private investors against hiking construction costs for the Winter Olympics in Sochi.

The 2014 Games are expected to cost $51 billion, including construction of new roads and railways, making it the most expensive Olympics in history.

Putin toured some of the Olympic venues on Wednesday, a day ahead of the 1-year countdown to the games.

Russian news agencies quoted Putin as telling investors and officials "the most important thing is that nothing gets stolen and that there'd be no unjustified hikes in spending."

Russian officials have dismissed allegations of corruption linked to the preparations for the games.