A total of 27 MPs are letting out property they have in London while claiming Commons expenses to rent homes, it has emerged.
An investigation by the Daily Telegraph using parliamentary records found former ministers were among the group that received taxpayer funding to live in the capital.
The move does not break any parliamentary rules but is likely to fuel calls for expenses rules to be toughened up.
Research by the Press Association found that shadow ministers Andy Burnham and Chris Bryant, and Tory MPs David Amess and Liam Fox receive income from letting out flats in London while also claiming expenses for renting in the city.
The Telegraph also named former defence ministers Peter Luff and Sir Nick Harvey among the 27.
Mr Luff declined to comment on the claims but according to the paper, he lets one small residential property in London he owns jointly with his wife but also claimed £17,799 in expenses for rental payments in the last financial year.
Concerns have also been raised that a "loophole" in the rules allows MPs to profit by renting properties to colleagues, who then claim the costs on expenses. It is understood that four MPs are currently renting from other MPs - although there are no cases of home "swaps".
Linda Riordan, the Labour MP for Halifax, rents her London flat to fellow Labour MP Iain McKenzie for £18,720 a year, according to the Daily Mail.
Mr McKenzie told the paper: "If I had known beforehand that the flat was owned by an MP then I probably wouldn't have taken it. You've got to apply the test of how it looks to the man in the street, regardless of whether it's above board or not."
Commons Speaker John Bercow was accused of trying to suppress details of the matter after warning the Independent Parliamentary Standards Authority (Ipsa) that revealing the identities of politicians' landlords would be a "security risk".