"The Mi-8 left [town of] Ust-Kut to carry out the geological survey. The crew failed to make contact at the set time," the representative from the regional emergencies services said.
He pointed out that three people had been on board the helicopter.
"The Mi-8 flew out of Ust-Kut and had to return, but did not return, and did not get in touch. A search is being conducted by forces from the Russian Ministry of Emergency Situations," the press service official said.
The Mi-8 helicopter belongs to the company Angara Airlines.
The Russian Federal Air Transport Agency has organized a search operation for the helicopter using other Mi-8 helicopters.
Further information about the incident have not been made available yet.