A VEIL of secrecy has descended on a St John s Wood school after a practical joker was allegedly expelled for a prank involving a fake gun. A pupil at the American School in London on Waverley Place is believed to have hidden backstage during an assembly

A VEIL of secrecy has descended on a St John's Wood school after a practical joker was allegedly expelled for a prank involving a fake gun.

A pupil at the American School in London on Waverley Place is believed to have hidden backstage during an assembly dressed as Heath Ledger's Joker from the Batman movie The Dark Knight.

He then leapt out brandishing the toy gun and waving it about - apparently causing alarm among the audience.

Parents and teachers were remaining tight- lipped when the Wood&Vale spoke to them about the incident, but pupils have confirmed the incident did happen.

A security guard quipped "news travels fast" when asked what had happened to the prankster but no information was officially forthcoming from the school.

Friends have since rallied behind the expelled pupil. Many say his expulsion for the joke is unfair because most people found it funny and were not at all frightened.

By yesterday 75 friends had joined a social networking group on Facebook in honour of their "legend" friend saying: "For all who wish to honour the prankster and his crazy Joker prank in front of the entire high school.

"For all who wish to speak out about the injustice of his expulsion. For all who want to remember him for the legend he truly is."

According to pupils the prankster is the third person to be expelled in three months. He has reportedly been completely banned from entering the school even to pick up his belongings or his work files from the computer.

The youngsters are worried that expressing their views on Facebook may result in them getting into trouble.

One said: "Guys, be careful about what you say... you may get expelled!"

But another retorted: "First amendment - free speech - and they can't stop anyone from thinking it..."

It is understood parents were reassured by the school about security after the prank.

A spokesman for the school said: "The American School in London has declined to comment. It is the school's policy not to make any public statements about internal events or circumstances involving students or faculty at the American School in London out of respect for the privacy of the individuals involved."

The American School has very tight security with guards around the school at all times and is renowned for its close-knit community. It is a private school with 1,300 pupils, which follows the American education curriculum.

Some of the most high-profile parents - including Russian billionaire Roman Abramovich - send their children to the school where annual fees cost up to £17,500. Former pupils include famous prankster Steve O from the Jackass television series.