The student behind a blog critical of his school was reported to the police by his headteacher.
According to the Camden New Journal, Hampstead School head Jacques Szemalikowski has also banned the website, The Hampstead Trash, from school computers.
Kinnan Zaloom, a 19-year-old who set up the blog in February this year, has also been told not to return to the grounds of the school.
And his headteacher is also reported to have told Glasgow University, where Zaloom had hoped to study, about the blog.
The blog, which Zaloom compares with Private Eye, has criticised the school on a number of counts, including for not listening to student views enough and failing to push GCSE results to a higher level.
The New Journal reported that Szemalikowski had taken action because of fears that Zaloom could be “developing into an anarchist”.
Szemalikowski told the paper: “I must do something. In the last year he has become more and more enchanted by anti-establishment ways of thinking and has even said that there is an inherent risk that every government is corrupt.
"I phoned Glasgow to warn them what sort of person they were dealing with, to advise them that this person thinks thoughts like these, and they could then make an informed decision. I am duty bound to do that.”