Sir Hector Sants, a former chief City regulator, is due to give evidence to the high court in private in relation to a case brought by Lloyds Banking Group shareholders over the information they were provided at the time of the HBOS takeover in 2008.
Hector Sants' break from his role as Chief Compliance Officer at Barclays due to stress has highlighted the strains on banks' internal policemen.
One of the most senior bankers of his generation.
Hector Sants, Britain's top financial regulator during the 2008 banking crisis, has been awarded a knighthood, weeks before he takes up a new post at Barclays bank on a pay package worth a reputed £3m.
Barclays has appointed Hector Sants to the newly created role of Head of Compliance and Government and Regulatory Relations. Sants will join the Executive Committee of Barclays and report directly to the Group Chief Executive Antony Jenkins.