London, Mar 6: Brit actor Daniel Radcliffe, 19, has written a heart-felt note to pay tribute to his murdered ‘Harry Potter’ co-star Rob Knox.

In the note to the mother of the 18-year-old knife victim, Radcliffe and the devastated cast and crew of ‘Harry Potter and the Half-Blood Prince’ penned down moving tributes to him.

The messages were written down in a copy of JK Rowling’s novel, on which the film was based, turning it into a treasured book of condolence for Rob’s mother Sally.

“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 Sun quoted Radcliffe as having written in the message.

He ended the message with a quote that famed author DH Lawrence had sent to a friend in 1923.

“To everyone else who reads this remember ‘The dead don’t die. They look on and help’,” he wrote.

Actor Rupert Grint, who played Ron Weasley, also paid tribute to Knox.

“Rob, It was an honour to have known you and whenever I’m on the Southend strip I’ll be thinking of you. Rest in peace mate,” he wrote.

Knox’s mother Sally, 51, who was relieved that her son’s murderer Karl Bishop, was given four life sentences at the Old Bailey, was touched by the messages.

“I know that people will look at these and think it’s nice because he was so high profile. But to me I treasure it because it was just another example of the way Rob touched lives, another person who met him and liked him. That’s what makes me so proud,” she said. (ANI)