Sergei Tsivilyov, governor of the Kemerovo region where the mine is located, on Friday said the survivor was found in the Listvyazhnaya mine in southwestern Siberia, and "he is being taken to the hospital".

No details of who the person was or where he was found were offered.

Six bodies were also recovered, bringing to 20 the number of confirmed dead. Thirty-one people are still missing.

Hours after a methane gas explosion and fire filled the mine with toxic fumes on Thursday, rescuers found 14 bodies but then were forced to halt the search because of a buildup of methane and carbon monoxide gas from the fire.

Another 239 people were rescued; 63 of them, as of Friday morning, have sought medical assistance, according to Kemerovo officials.

The state Tass and RIA-Novosti news agencies on Thursday had cited emergency officials as saying that there was no chance of finding any more survivors.

It was the deadliest mine accident in Russia since 2010, when two methane explosions and a fire killed 91 people at the Raspadskaya mine in the same Kemerovo region.

Regional officials declared three days of mourning. Russia's Investigative Committee has launched a criminal probe into the fire over violations of safety regulations that led to deaths. It said the mine director and two senior managers were detained.

Australian Associated Press