Ten senior case officers have abruptly left the Serious Fraud Office (SFO) with payouts of up to £200,000 each, The Times has learnt. They left under the Management Approved Voluntary Early Release scheme — effectively a voluntary redundancy option. The total bill could be £2 million.

The exodus comes less than a year after Richard Alderman, a former HM Revenue & Customs official, succeeded Robert Wardle as director of the SFO. He is understood to have clashed with many of those leaving over direction. Mr Alderman favours focusing on preventive measures — such as appeals to whistleblowers — rather than long investigations.

Operation Holbein was a four-year inquiry that sought to establish price-rigging among drugmakers, but that proved a huge embarrassment to the SFO when it collapsed last year. The inquiry cost at least £14 million to mount. There was a further blow three years ago when the SFO's investigation into the Saudi activities of BAE Systems was blocked by the Government.

The departures come just as the SFO's workload is increasing because of scandals, such as Bernard Madoff's, exposed by the recession. The highest-profile name among those departing is Philip Lewis, former SFO deputy director, and the man behind Operation Holbein. Also leaving is Julian Parker, who was principal divisional investigator and one of the SFO's top officials.

Graham More, assistant director and another experienced SFO hand, is another to have departed. Emma Lindsay, a case controller, Stephen Lowe, the chief accountant, Jane Astley, Christian Maccaulay, Steve Crundarm and Belinda Thamar have also left. The SFO did not return calls seeking comment.

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