Three redundant water cannons bought by Boris Johnson when he was London Mayor and costing more than £300,000 have been sold to a Nottinghamshire firm for scrap - for just £11,000.
The cannons were bought more than four years and never used.
But current Mayor of London Sadiq Khan has now announced that they have been sold, with funds from the sale to be invested in projects to tackle the root causes of serious violent crime.
The cannons were purchased from the German Federal Police for £85,000 in June 2014, but official approval to use them on the streets of London had not been granted.
An additional £240,000 was then spent to restore the cannons, before former Home Secretary Theresa May, refused permission for their use in London in July 2015.
The water cannons have been on the market since December 2016, and have now been sold to Reclamations (Ollerton) Ltd for £11,025.
The money will be directed towards frontline young and community services as part of the Mayor's Young Londoners Fund.
The Mayor of London, Sadiq Khan, said: “For too long, London taxpayers have had to bear the brunt of Boris Johnson’s appalling botched water cannon deal.
"This has been another waste of taxpayers’ money by Boris Johnson. Londoners continue to live with his vanity.
"I am pleased we have managed to finally get rid of them and I made an election promise to Londoners that I would claw back as much of this cash as possible, and pump it into helping young people at risk of being affected by crime and giving them better life opportunities.
“By working with communities and giving young Londoners meaningful things to do, I am doing everything I possibly can to help ensure they make the right choices and do not follow the wrong path at such an important time in their lives."