Police are investigating after a machete was discovered behind a wall in Welwyn Garden City.
Officers collected the blade from Howardsgate on Saturday morning (March 9th) at around 7.45am.
A spokesperson for the Constabulary said: "It would not be appropriate to comment further at this time."
It comes as Herts Police joins a nationwide crackdown on knife crime, with such incidents increasing across the county in recent years.
As part of the amnesty, blades can be dropped in bins at Hatfield, Stevenage or Watford Police Stations. This can be done anonymously and without fear of prosecution for possession of these items.
A temporary knife bin will also be in place at Sainsbury in Potters Bar on Tuesday March 12 between 3pm and 5pm and at the Furzefield Centre in Potters Bar on Wednesday March 13 between 3.30pm and 5.30pm. There will also be permanent knife surrender bins in Waltham Cross details of which can be found at www.herts.police.uk/amnesty.
The amnesty also provides an opportunity to educate young people about the dangers of carrying a knife, give crime prevention advice and raise awareness amongst local businesses that selling certain knives to anyone under 18 is illegal. As part of a wider campaign officers will be carrying out knife detection operations, test purchasing at knife retailers and visiting schools to deliver talks on the dangers of carrying a knife.
Inspector Andrew Palfreyman, who is leading on the operational activity for Operation Sceptre, said: "As part of our wider plan to reduce violent crime we continue to support Operation Sceptre and I encourage people to take advantage of the knife amnesty.
"During the week of action we will also be conducting other operations to reduce knife-related crime, as well as using a poster campaign and social media to help raise awareness, especially among young people, that carrying a knife will not make you safer and is not acceptable in our county."
Hertfordshire's Police and Crime Commissioner, David Lloyd, added: "Violent crime remains relatively low in Hertfordshire, and previous amnesties have been very effective in reducing the number of knives in circulation.
"We are developing new initiatives to help young people understand that carrying a knife is not acceptable, is illegal and you are more likely to be injured or arrested if you choose to carry one.
"The amnesties are now a regular part of our violent crime reduction plan and any knives that can be taken off of our streets will help to make everyone safer."