Shareholders in some of the UK’s largest water companies have taken out tens of billions of pounds but failed to invest, new research claims, with firms planning to raise household bills to fund future spending.

Investors have withdrawn £85.2bn from 10 water and sewage firms in England and Wales since the industry was privatised more than 30 years ago, analysis by the University of Greenwich suggests.

Companies are under pressure following sewage spills and water leaks, which critics have blamed on under-investment in the country’s infrastructure.

Ofwat, the industry regulator, said it “strongly refuted” the figures.