Students browsing the website for Tiffin School for Boys found it had been hacked and redirected to a porn video this week.

Tiffin School in Queen Elizabeth Road is said to have had problems with hackers in the past fortnight, but the issue escalated on Monday evening when students logged on to their school website only to be redirected elsewhere.

A police investigation has now been launched into the internet security breach at the high-achieving grammar school.

A Richard Challoner School pupil, who did not want to be named, said: “It was pretty crazy. My mate told me about it and I went on to the computer to see what was going on.

"The video showed a man and a woman having sex in a loop – so you couldn’t stop it.

"The school was pretty quick in closing the site down though – but it’s just crazy. The rumours are that it was someone at the school.”

On Twitter MMTrollface appeared to take the credit for the hacking.

He told one user who criticised him: “I’m not the one who attends an all-boys school”.

A spokesman from Kingston police said: “Kingston police can confirm they are investigating the hacking of Tiffin Boys’ school website which occurred on Monday, March 18.

“The website was redirected to a number of different sites before being shut down. No arrests have been made at this stage.”

Simon Toyne, assistant head at Tiffin School, said: “Investigations are ongoing, so we do not wish to comment further at the moment.”

One parent said in an 11-plus internet forum: “Maybe they should pay more attention to website security.”

Another said: “Shocking but I guess that’s the downside to having super intelligent pupils (if it was a pupil).

"Maybe it was a disgruntled parent whose son didn’t get a place?”