The fire started on the night of March 24-25 in the Lenkom Theater premises leased by a night club.
"The bodies of the dead persons were found during the effort to put out the fire. Their identity is being established," said Yevgeny Bobylev, a spokesman for the Moscow department of the emergencies ministry.
According to the spokesman, most of the persons killed in the fire died of carbon monoxide poisoning while four people were hospitalized.
A total of 150 people have been evacuated from the fire-stricken night club, Bobylev said.
Rescuers are continuing to clear up the debris and the death total could rise, Bobylev said.
An investigation is under way to establish the cause of the fire, with arson being considered as one of the versions, the spokesman said.