The MPs are thought to include a former Labour cabinet minister, two Labour MPs, two Conservatives and a Liberal Democrat.
The allegations are said to relate to inflated claims for household expenditure such as council tax, maintenance and utility bills.
According to the Sunday Times, the allegations have been made by a Labour MP, who represents a northern constituency, who passed details of alleged wrongdoing to police because he believes he was unfairly singled out for investigation over his own allowances.
If confirmed, it would be the first time since the expenses scandal erupted in 2009 that an MP has made a complaint to police about fellow members of the Commons.
Scotland Yard said on Saturday that “a small number” of parliamentary expenses cases remain under consideration by a panel of detectives and prosecutors, but was unable to say whether any fresh cases had been brought to their attention recently.