The British government auditor raised concerns about a 422,000 pounds severance given to the former head of the national anti-fraud body, the National Audit Office said on Thursday.

The auditor took issue with the severance terms of former Chief Executive Officer Phillippa Williamson agreed to by previous Director Richard Alderman in April this year.

"The Serious Fraud Office (SFO) entered into an agreement which forced it to make irregular payments," said Amyas Morse, head of the National Audit Office (NAO).

The NAO said the fraud-fighting body should have tried to find Williamson a different job in the Civil Service and sought approval for two payments of 407,000 pounds and 15,000 pounds.

The present director, David Green, called a full independent inquiry on learning of the terms after he replaced Alderman in April.

Green tried to claw back what he considered "unjustified expenditure" and decided not to seek retrospective approval from the Treasury for the severance package, according to the SFO website.

British politicians in the House of Commons may now take on the case, according to the NAO.

(Reporting By Dasha Afanasieva; Editing by M.D. Golan)