This is the horrific moment that a bullied Russian teenager suffocated on his classroom floor after falling on a desk and crushing his oesophagus while his tormentors stood around laughing.

Sergei Casper had been tied up so he couldn't move his arms or legs and dunked in a toilet by bullies who then carried him back into the classroom in front of their teacher and stood him at the back of the class.

Still tied up and unable to walk the 17-year-old appears to stumble forward at which point he falls awkwardly onto the edge of a desk hitting his throat.

Horror fall: Russian student Sergei Casper fatally hits his throat on the edge of a desk crushing his oesophagus after being tied up by bullies and dunked in a toilet

The injury left him unable to breathe but instead of coming to his aid, his heartless classmates stand around laughing.

By the time they realised he was having a serious problem and called the ambulance, it was too late.

Casper had reportedly been a hardworking and popular student at a previous school but that all changed when he joined Polytechnic College number 8 on Dmitrov Shosse street in the Russian capital Moscow.

Classmates started bullying him because of his love for the arts and his desire to perform on stage taking part in several concerts.

The student, still tied up, is hauled to his feet by one of his classmates but he had suffered a crushed oesphagus which had left him unable to breathe

By the time classmates realised that the student was having serious problem and called the ambulance, it was too late

One of his friends, named Alexander, told local media: 'He was a good guy, he never did anything bad to anyone and he was my friend. But the others just picked on him all the time.'

He said that on the day died, they had been waiting for him in the corridor as video footage confirms, and had grabbed him and carted him off to the toilets.

Alexander added: 'They seemed to think it was hilarious, and then they decided to take their prize back to the classroom where although the teacher was sitting at her desk, she did absolutely nothing to help him.

Investigators who studied this video said it showed clearly that the blame for the deaths was on the classmates of the 17-year-old, and the school has denied that they were aware there was a bullying problem at the institution.

Classmates reportedly started bullying the victim because of his love for the arts and his desire to perform on stage taking part in several concerts

They also added that those involved in the bullying had been expelled.

One of those involved, called Dmitri, tried to defend the action saying it was simply a joke that had gone wrong.

However the parents of the dead boy have demanded to know why the teacher was in the class did nothing, and quote schoolfriends who say that the bullying had gone on for months with nobody doing anything.