The brutal killing of a Harry Potter star from Kent nearly 15 years ago will be explored in a documentary this week.

Rob Knox, from Swanley, was stabbed five times while trying to protect his younger brother in a bar brawl in Sidcup back in May 2008.

The 18-year-old had just finished filming alongside Daniel Radcliffe in Harry Potter and the Half-Blood Prince and was set to reprise his role as Marcus Belby for the film series final instalment The Deathly Hallows.

Tomorrow (Thursday) the award-winning documentary (K)Nox: The Rob Knox Story, will be available to watch on ITVX.

It hears from the Kent man's family, friends and Harry Potter cast members – including Jim Broadbent (Professor Slughorn), Tom Felton (Draco Malfoy), and David Yates (Director) – who speak about the young actor's life and shock death.

In March 2009, just less than a year after Rob's killing, Karl Bishop was found guilty of murder.

Bishop, who was 22 at the time, was given a life sentence with a minimum of 20 years before parole.

At the time, Mr Justice Bean described him as a "dangerous man".

He said: "I do not think it is proved that you intended to kill Robert Knox.

"The truth is that you simply could not care less whether you killed him or not. Your lack of regret let alone remorse was truly chilling."

The film was previously named Best Feature Documentary at the 2021 London Independent Film Festival and looks to address the growing knife violence problem in the UK.

A synopsis from Q Cumber Films explains: "Eighteen-year-old Rob Knox is out celebrating his big break in Harry Potter when he learns that his little brother has been threatened at knife-point. He and his friends rush to disarm the man but during the struggle, Rob is stabbed several times and is killed.

"Now his family must try to navigate their grief and anger while under the ever-watchful eye of the invasive British media machine.

"Meanwhile, more young people than ever are losing their lives on the streets. Something has to be done."

A decade after his son's death, Colin Knox spoke out about the worrying rise in knife violence around the UK.

Rob's parents have previously fought for stricter sentences around knife crime.

Rob also appeared in ITV's The Bill, Channel 4's reality show Trust Me, I'm A Teenager, and BBC comedy After You're Gone.