MP for the cities of London and Westminster Mark Field has failed in his attempt to force the regulator to pay for section 166 reports.
In March, Field tabled an amendment to the Financial Services Bill that would have required the regulator to fund section 166 reports and recoup the costs only in cases where it leads to enforcement action.
The amendment was not selected to be voted on in the House of Commons during a debate on the bill on Monday, which was the last time the amendment could be passed in the Commons.
Field told Parliament the change is vital because the cost of the investigations, which falls on firms, has risen almost 10-fold since 2005/06 when there were 18 investigations at a cost of £3.8m.
By 2009/10, that figure had risen to 95 cases at a cost of £32.2m.
Field said the reports are increasingly being used as a “standard regulatory method” rather than being reserved for the most serious cases.
He said: “Under the current regime, firms are guilty until proven innocent and they have to pay for their own prosecution, regardless of whether guilt is proved or not.”