Daniel Radcliffe remembered touching moment with Harry Potter co-star who tragically died before movie wrapped

Daniel Radcliffe spoke very highly of one of his late Harry Potter cast mates in a documentary about his life.

The Wizarding World franchise has seen the deaths of many of its stars in the past few years, from Alan Rickman (Snape) to Michael Gambon (Dumbledore), but there was one star who passed away before seeing himself in the series.

His name was Rob Knox, and the British actor played Marcus Belby in Harry Potter and the Half-Blood Prince.

Though he only played a bit part role in the sixth instalment of the film franchise, true Potterheads will remember Knox's appearance.

He had signed on to appear in the Deathly Hallows despite his character not appearing in the book, but the then-18-year-old was tragically killed before production began.

Outside a pub in Sidcup, Southeast London, on 24 May 2008, Knox got himself in the middle of a fight between his brother and a man holding two kitchen knives.

In his attempts to help his brother, the actor was tragically stabbed to death.

Following Knox's death, Warner Bros. subsequently released a statement, saying: "We are all shocked and saddened by this news and at this time our sympathies are with his family."

The 18-year-old hadn't even managed to see his appearance in the Half-Blood Prince, as it was released in theatres the following year in 2009.

He was described as a 'typical teenager with a great sense of humour', with his whole life and career ahead of him.

Knox was just 18 when he was killed (ITV)

A documentary on the late actor's life was released by ITV in 2021, called (K)Nox: The Rob Knox Story.

In the opening seconds of the doc's trailer, we get a couple of tributes from some of the franchise's stars, with Tom Felton (Draco Malfoy), saying: "I remember Rob being quite the joker, being quite joker, I mean probably as myself, to be fair."

Daniel Radcliffe, the man behind Potter himself, recalled: "I did one scene with him and you could tell just from that and the commitment that he entered into it with, that he was good."

Directly following Knox's death, Radcliffe also shared an emotional message: “Dear Rob, We are all proud to have known you and devastated to have lost you. It is terrible just to write this note. Rest in peace, Dan xxx.”

The perpetrator, Karl Bishop, 22, was found guilty of stabbing Knox five times, and was handed a life sentence with a minimum of 20 years before parole.

Despite having a short time on set, Knox left an impression on his cast mates (ITV)

The documentary focuses on the lead up to the horrific incident, how the family have dealt with their grief and loss, as well as the ensuing knife crime epidemic that swept the UK in the aftermath.

Speaking in court to Bishop at the time, Mr Justin Bean stated: "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."

(K)Nox: The Rob Knox Story is available to watch now on ITVX.