Storchak, who oversaw foreign debt talks at the ministry and was a key figure in Russia's talks with the Paris Club, was detained last November and accused of attempting to embezzle $43 million from the state.
Investigators said that they had taken a decision to release Storchak and a second suspect, Viktor Zakharov, general director of the company Sodexim, as the investigation was over and now they could not influence its results.
Russian prosecutors filed final charges against Storchak earlier this month. The investigation committee of the Prosecutor General's Office said that in addition to the embezzlement charges, Storchak had also been charged with abuse of office.
Storchak has maintained his innocence throughout the investigation. If convicted, he faces between five and 10 years in prison.
Russia's stock market has reacted positively on the news of Storchak's release from custody, which gave a boost to the ongoing stock price rally.
As of 3:00 p.m. Moscow time (11:00 GMT), the benchmark RTS index grew 4.59% on Monday's close to 732.59 points and the MICEX index climbed 6.43% to 666.68 points.
