The child, known only as David K, was reportedly found with a gag stuffed in his mouth in the Yugo-Zapadny district of Yekaterinburg, Russia.

Police say members of the Disciples of Jesus Christ sect held him down and whipped him to "drive out demons".

David allegedly died after the gag cut off his oxygen. The cultists then prayed by his body for two days after he died in an attempt to "resurrect" him, according to media reports.

But when this failed, his body was buried and remained hidden until a tip-off from David's aunt led police to the body. A postmortem revealed that his body was covered in welts when he died.

His father has been detained on suspicion of murder. Some media report his mother has fled the country, and Russia is now seeking her extradition.

A female sect leader named Zemfira Gainullina posted online shortly before her arrest.

"Many times we were persecuted for the name of Jesus Christ, but no-one could blame us for anything, because there was no crime in us.

"No-one could forbid us to live the way the Lord Jesus Christ leads us."