By Claire Duffin For The Daily Mail
Published: 01:23 GMT, 7 December 2018 | Updated: 02:30 GMT, 7 December 2018
Children as young as four were reportedly left in tears after being told Santa was 'made up' during a Christian assembly.
Pupils were then asked to smash up chocolate versions of St Nicholas and his reindeer to hammer home the point.
Parents said their children had come home feeling devastated following the sermon by a children's worker from a Christian charity.
The head teacher of Fleet Wood Lane School in Spalding, Lincolnshire, insisted that the children were not told 'Santa does not exist', but has since apologised and said the school would no longer be working with the group.
Children as young as four were invited to smash up chocolate replicas of Santa Claus and his reindeer [file photo]
The Mary Bass Charity, which seeks to 'further the religious and other charitable work of the Church Of England' in the Lincolnshire district of South Holland, said it was investigating.
It is understood the woman delivering the assembly on Thursday was trying to explain to children that Jesus was the reason behind Christmas, not Santa, who had been 'made up'.