The cast of the new Harry Potter film will wear white ribbons on their wrists at tonight's world premiere as a mark of respect to murdered actor Rob Knox.

The 18-year old from Maidstone Road, on the border of Swanley and Bexley, had just finished filming his role in Harry Potter and the Half Blood Prince when he was killed.

He died after being stabbed five times outside the Metro Bar in Sidcup in May last year.

Karl Bishop, 22, from Sidcup, was jailed for life for his murder at the Old Bailey in March. He will serve a minimum of 20 years.

The film's premiere is being held in London's Leicester Square.