Schoolboy Ignat Sharapov, whose social media is full of Satanist signs and images, has told police he set fire to the structure by using five litres of petrol.
An expert said it will cost £1 million to reconstruct the 138 ft church – as tall as a 12 storey building – at Kondopoga in Karelia republic in northern Russia.
A law enforcement source said: “He classifies himself as a Satanist. Allegedly he just did not like the church.”