Thirty-five members of the sect went underground in the Penza Region in November 2007 to wait for the end of the world, which they say will come in May or June. Two members of the sect have since reportedly died, their bodies apparently buried in the shelter. Another 24 members, including four children, left the dugout around a month ago after most of the roof collapsed following heavy rain.
The remaining nine sect members had earlier promised to come to the surface today.
"I can say with 100% certainty that their plans to leave the dugout have changed," Sergei Nedogon said. His father, Vitaly, is one of the hardcore now refusing to come to the surface until after the Feast of the Holy Trinity.
A female sect member now above ground has confirmed the reports of deaths. Local authorities have not been able to verify the information, however.
The sect's leader, Kuznetsov, 43, was admitted to hospital in April after an apparent suicide attempt. Russian media initially reported that Kuznetsov, who did not join his followers underground, had been beaten by the emerging sect members after taking part in negotiations to persuade them to leave their shelter. He had been held in an asylum in Penza about 600 km (370 miles) southeast of Moscow since November.
Despite one member of the sect claiming that the group is an offshoot of the Jehovah's Witnesses, the sect has generally been considered part of a wave of extreme Russian Orthodoxy in Russia and some former Soviet republics.
Russia has seen a great number of sects throughout its history. One of the most famous of these was the Skoptsy, who castrated themselves to avoid sexual temptation and sin. The sect was first reported in the 18th century and is known to have still existed in the 1920s.
Another notorious sect was the Khlysty, an offshoot of the Russian Orthodox Church. The Khlysty believed that the way to salvation lay through the repentance of sins. The greater the sin, the greater the repentance, the Khlysty reasoned, and following this logic they rejected conventional doctrines of 'right and wrong', indulging in sins that they could later confess to, being in this way 'pleasing to God.' Grigory Rasputin, the mysterious monk who had a malign influence on the Tsar and the Tsarina prior to the 1917 Russian Revolution, is believed to have had links with the group, which was active from the 17th century to the early 20th.