Its demand was revealed in a statement to parliament from Solicitor General Robert Buckland and comes six months after the SFO requested a further £10m from MP's.
The SFO operates on an annual budget of around £33m, but is able to request extra funds from parliament. Buckland said the cost would cover "significant investigations and the settlement of material liabilities".
However, Labour has questioned the increase, questioning whether the funding method allows Chancellor George Osborne undue influence in prosecutions pursued by the fraud watchdog. And it is worth examining whether the SFO track record merits greater investment.