A student kicked out of school for dealing “fake” cannabis won the right to challenge his expulsion.

London’s High Court this week granted the boy, who cannot be named for legal reasons, the chance to clear his name by ordering a full re-hearing of his case.

The boy was expelled from his school in Sutton after he was accused of selling a substance which the buyers believed to be cannabis, the court heard.

The boy claimed the so-called “weed” was actually a herbal smoking substance he had bought legally in a shop and he had just been “showing off”.

However, an appeal against the school’s decision by the boy was rejected by a local panel.

The court heard that, although the boy has since got on with his life and does not want to return to his old school, he is “determined” to clear his name of the stigma of expulsion.

Mr Justice Hickinbottom ruled the appeal panel had not been “procedurally unfair” but said it had “erred in law” when it failed to find out whether the substance supplied by the boy was actually cannabis.

He said the lapse meant the panel had failed to properly consider whether expulsion was “a reasonable and proportionate” sanction.

Conservative councillor Paul Scully was critical of the judge’s decision to allow the re-hearing with a new panel.

He said: “Everybody has a right to clear their name if they think they haven’t got justice, but on the other hand, teachers are usually the best placed to make a decision.

“We would be looking to back the people that are best placed to know.

“The council appeal panel would also take a robust approach – it is not there to blindly do what the school does.

“I would also give the teachers credit, they are the ones at the coal face.”

Former Labour councillor Andrew Theobald, a father-of-two who has been a school governor in Sutton for 25 years, said it was reasonable for the case to go to be reviewed.

He said: “I’m a little bit surprised it has gone this far as I would expect the Sutton school and the local authority to have looked at it properly, however, putting my parents hat on, if I thought my sons had been treated unfairly, I would want to do everything in my power to clear their name.

“The school must protect the greater good, but permanent exclusion puts a permanent blot on a student’s school history and so it should be subject to scrutiny. ”