A film crew worker was allegedly slashed in the throat during filming for the remake of 'The Witches' at the Warner Bros studio.
Police were called to reports of a stabbing at the film studio, in Leavesden, Hertfordshire, at 12.30pm on Wednesday.
A man was taken to hospital in an ambulance suffering with a neck injury.
Another 54-year-old man was arrested on suspicion of wounding with intent to do grievous bodily harm.
Hertfordshire Police said the two men are understood to 'know each other'.
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It is understood the incident took place on the set of the film adaptation of Roald Dahl's The Witches.
The remake stars Hollywood actors such as Anne Hathaway, Chris Rock and Octavia Spencer.
Warner Bros Studio is located next door to where 'The Making of Harry Potter' tours take place.
Star Wars Episode One: The Phantom Menace and the Harry Potter series are some of the films to have used the site.
A Hertfordshire Police spokesman said: "Police were called at around 12.35pm today to reports of an incident at Warner Bros studio production facility in Leavesden.
"One man sustained a neck injury and was taken to hospital by ambulance.
"A second man, who is 54, was arrested on suspicion of wounding with intent to do grievous bodily harm and is currently in police custody.
"It is believed the men are known to each other. Enquiries are continuing at this time to establish the circumstances around what happened."
