Three water cannon bought and refurbished for more than £320,000 while Boris Johnson was London Mayor have been sold for £11,000.
The vehicles were bought by Mr Johnson as crowd-control weapons following the 2011 riots.
They were sold for £11,025 to Nottinghamshire-based Reclamations (Ollerton) Ltd who will dismantle them and export the parts.
Current Mayor Sadiq Khan said “we have managed to finally get rid of them”.
The vehicles were bought by Mr Johnson from Germany in 2014 – before their use had been licensed on the UK mainland.
Then-Home Secretary Theresa May banned their use in riot situations in 2015, and later used the purchase to ridicule Mr Johnson in the Tory leadership race after David Cameron resigned.
They cost £322,000 to purchase second-hand and then refit. Costs included £32,004 for low emission zone compliance, £19,035 for re-painting, £3,109 for signage, and £970 for the fitting of radios and CD players.
Mr 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.
“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.”
The sale was announced as details were revealed of 72 youth projects that will receive the latest round of grants from the Young Londoners Fund.
The schemes, which are aimed at diverting young people away from crime, will receive a share of £13.2m. The projects include the Ben Kinsella Trust, Redthread and Football Beyond Borders
Mr Johnson is yet to comment.