The Metro story based on a study from Exaronews.com said the subsidy is helping to inflate house prices and saving landlords £2bn a year in tax benefits, which is an average of £1,400 per property.

The website suggests millionaires are using the mortgage interest loophole to cut their tax bills down to zero.

The Treasury has no intention of stopping buy-to-let investors from deducting mortgage interest from earnings, confirmed the story.

A spokesman from HM Revenue & Customs said:

“There is no such thing as a buy-to-let tax break. It is simply a business cost which is a claim against tax, the same as any other business.”