Anyone wanting to dispose of knives “with no questions asked” can just drop them into the bin at Willesden Community Gardens in Denzil Road, near the College of North West London.
It has been added to the seven amnesty bins already installed by Brent Council as part of a three-year Home Office programme to get deadly weapons off the streets.
“This is a discreet way to surrender dangerous weapons that are now illegal,” the council’s cabinet member for public safety Harbi Farah said.
“Take this opportunity to get rid of these weapons responsibly if you or someone you know possesses a ninja sword. Every weapon taken off the streets helps make the community safer.”
The bin has a special chute at the top to take larger ninja swords and machetes and another slot for smaller, standard-size knives.
Anyone with a weapon they want to dispose is being urged to wrap it securely in several layers of cardboard or thick paper to cover the blade or sharp edges completely, then seal it with strong adhesive tape to make it safe on the way to the bin.