Writing in The Daily Telegraph, Ofwat Chairman Jonson Cox, has voiced his concern over water profits and taxation.
He said: "It has also been alleged that some companies use shareholder loans to avoid UK taxation.
"At the same time, hard-pressed customers have seen annual bills rise by 13.5pc since 2010-11, while their incomes have fallen.
"I agree that the dichotomy between profits and the prices charged to customers raises business, regulatory and moral questions."
More top news
Dan Ware, whose house caused a storm last year when it was posted on Twitter, says the Tories "care more about hardworking Brits"