Police: "Ninja swords serve no purpose other than to kill or maim."
A month long amnesty is taking place this July.
Surrey Police have told Greatest Hits Radio that ninja swords serve no purpose other than to kill or maim.
This comes as next month, owning one of these swords will become a criminal offence.
It is already a criminal offence to carry the weapons in public, however starting in August, it will be a criminal offence to possess, manufacture, import or sell a ninja sword.
Mark Offord, who is Surrey Police lead for knife crime, says that this ban will stop the supply increasing and will make it less likely for these blades to fall into the hands of people who want to cause harm.
"They're being banned because actually they're there to serve no other purpose other than to kill or maim people."
"Ninja swords are a particular type of martial art weapon, which we know are popular with collectors, people interested in martial arts. But they're designed with one thing in mind only, and that's to cause harm."
Throughout this month, people who own ninja swords will be able to hand it in at a police station and receive compensation as part of the nationwide amnesty.
Mark added that these schemes are commonly successful.
"We have found in previous surrender schemes there's been really good engagement from the public who understand the need to take these items off the street."
Weapons can be surrendered at Guildford Police Station, Staines Police Station, and Caterham Police Station.