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
Demonstrators have blockaded the entrance tunnel to Heathrow Airport in apparent protest at plans to build a third runway.
A man was left red-faced after neighbours reported shouting and a woman screaming - which turned out to be his efforts to kill a spider.
A man who shot and killed his wife before posting a photo of her body - and a confession - to Facebook has been found guilty of murder.