Rescuers have found a survivor in a Siberian coal mine where dozens of workers are presumed dead after a devastating methane explosion.

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

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

Hours after an 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 build-up of methane and carbon monoxide gas from the fire.

Another 239 people were rescued and 63 of them needed 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 investigation into the fire over violations of safety regulations that led to deaths.

It said the mine director and two senior managers were detained.