A teenage boy was arrested after threatening Lewisham police officers with a 20-inch knife from the film Predator.

The 15-year-old was caught with the massive blade near Downham and was also found in possession of cannabis.

Lewisham MPS tweeted a photo of the huge knife, which is engraved with the title of the 1987 Arnold Schwarzenegger sci-fi film, and the signature of his character Major 'Dutch' Schaeffer.

The prop replica knife is available to buy online at just £29.95, and has a 14.75-inch stainless steel blade.

The boy was bailed to appear in court later this month.

In a tweet the police said: “A fifteen year old male has just been arrested after threatening police officers with this terrifying blade in Ambleside, Downham.”

In a follow up message they said: “The 15 year old male with the large knife was charged with affray & possession with intent to supply cannabis. Bailed to court 16/11/17.”

Other twitter users replied in shock at the size of the knife, and @MPSLewisham said: “Sadly it's not so shocking to us. It's all too frequent.”

One user asked: “That is ridiculous !! Does that even have any kind of legitimate use ??”

MPSLewisham replied: “Worryingly they are as easy to order as an 18 rated video game or movie. Designed to kill under the guise of a movie prop imitation.”