The private equity veteran Jon Moulton has joined Roman Abramovich and a son of the late Sir James Goldsmith in backing the producer of Britain's only herbicide-free weedkiller.
Moulton and his family contributed to Weedingtech's recent £750,000 fundraising, which takes the company past its £2m funding target.
Weedingtech raised its first instalment of finance in August from investors including Abramovich, who owns Chelsea FC, and Ben Goldsmith. Weedingtech's product is Foamstream, which kills weeds using foam, hot water and steam instead of chemicals. Abramovich invested through Ervington Investments, which he set up to fund clean technology.
Goldsmith, an environmental campaigner and the brother of the Conservative MP Zac Goldsmith, helped found Weedingtech, . The company developed Foamstream with Cambridge University's department of plant sciences, and sells the weedkiller to local councils and water companies.
As well as being environmentally friendly, the product is a potential growth market for investors as governments tighten restrictions on the use of chemical weedkillers.
Moulton said: "This is a sizeable market opportunity that is only going to get bigger as more traditional herbicides are legislated against. Weedingtech have the right products, platform and expertise to capture a commanding position in this new marketplace."
Moulton is known as a maverick in the private equity industry, which he has criticised for exploiting tax loopholes in the past. He tried to buy MG Rover in 2000, and has more recently invested in Reader's Digest UK.
Weedingtech will use the money it has raised to expand its product range and to market Foamstream in the UK and Europe. It plans to make weedkillers for household and agricultural use.
The funding round also got support from Clearly So, a social finance organisation that taps a network of wealthy investors.
Sophie Marple, one of the investors, said: "This technology could transform the weedkiller market, and by investing in them through Clearly So I hope to become part of its journey to success."