But the youngster, who had several allergies, was subjected to a prank at school at William Perkin C of E High School, Greenford, west London, fellow pupils said.

At lunchtime on 28 June cheese was flicked or thrown into Karan's face.

He later went to the school's office where allergy medicine is kept but staff were unable to help and called an ambulance.

Karan died in hospital less than two weeks later surrounded by his family.

A 13-year-old boy at the same school was arrested on suspicion of attempted murder on June 28 and has since been released on bail.