Rupert Soames is joining Serco as its chief executive a month earlier than expected as the security giant looks to quickly rebuild its reputation in the electronic tagging scandal's wake.
Serco said in a brief statement that Soames, who is the grandson of British wartime prime minister Winston Churchill, will now take the helm on May 1 rather than in June. He joins from his role as boss of energy firm Aggreko.
The business is under criminal investigation by the Serious Fraud Office (SFO) after it emerged that the Ministry of Justice had been overcharged on Serco's contract to carry out the electronic tagging of criminals.
In some cases it was alleged that taxpayers were billed for tagging work that was never carried out. Serco's rival G4S, another outsourcing firm, is also caught up in the scandal.
When the SFO investigation was announced, Serco's then chief executive Christopher Hyman quit.
Serco was subject to a ban on government contracts until early 2014 as a result of the tagging furore.
It has also paid back £68.5m to the Ministry of Justice and is undertaking a costly "corporate renewal" programme to refresh its culture, structure and processes.
To add to the company's troubles, it reported a 3.6% fall in profit for 2013 and warned of a difficult year ahead in 2014.