A Bungay-based firm which makes solar-powered irrigators for smallholder farmers in Africa and Asia has raised £600,000 from ethical investors in more than 50 countries - in just a week.

Futurepump has already doubled the £300,000 target it set when it launched its share offer via crowdfunding website Crowdcube on March 3.

The firm, which has a manufacturing base in India but whose HQ is in Wainford, near Bungay, says the extraordinary response from more than 1,000 new investors will help the firm grow and drive down the costs of getting their solar technology to rural farmers in some of the world's poorest communities.

Founder and managing director Toby Hammond said he was keen to avoid the conventional corporate venture-funding route, and instead offer customers across the world a chance to own part of the company.

"I’ve been burned in the past by choosing the wrong investors, and we all felt that crowdfunding was a far better fit with our company ethos, because everyone can get involved, from as little as a £10 investment.

“Our small team has built an amazing company because we all believe passionately in the social and environmental impacts of what we do, and this past week shows us that investors also want more than just a financial return.

"It is a game-changer for us. This money will enable us to really step up a gear in terms of our ambitions.

"But we also have this army of advocates, people who believe in what we are doing and have put their hands in their pockets. They range from barristers to hedge fund managers, farmers and solar experts. We are looking forward to involving them in what we are doing to bring this transformative technology to smallholder farmers across the tropics."

Mr Hammond said the business was founded in 2013 following a "chance YouTube encounter" with the Dutch inventor of a solar-powered irrigation pump. Since then, the firm has sold more than 8,000 units through a network of distributors in 20 countries throughout Africa and Asia.

"There is something like half a billion smallholder farms in the world, and if you look at Africa 80pc of the food is grown by small-scale one-acre farmers," he said.

"Unfortunately these farmers are also very low-income and are on the frontline of climate change. Rainfall patterns which they used to rely on are no longer as reliable. But there is no shortage of sunshine, so solar pumps offer a great solution to the problem of getting water to their crops.

"We are displacing petrol pumps so it is good environmentally, and it is good socially because we are helping some of the poorest communities in the world. But it is also good business. People, planet and profit is a good mix for any company."