Roger Jenkins is on trial with two other former Barclays executives over how the bank secured around 4.0 billion pounds in rescue financing from the Gulf state in 2008.

Jenkins, who was recommended for a 25 million pound bonus for arranging the Qatari investment over June and October 2008, was briefly rattled when prosecutor Edward Brown asked whether he had merely sought to look after his own interests.

"So in answer to your question, Mr Brown, ... I had a heart attack on August 5 (2008) and I was instructed to get out of my bed, leave my family on August 29 and come back to work to help this bank survive," 64-year-old Jenkins told the jury at the Old Bailey criminal court.

Barclays avoided the fate of rivals Lloyds and Royal Bank of Scotland and averted a state bailout by raising a total of 11 billion pounds over 2008.

But prosecutors for the UK Serious Fraud Office allege the three men lied to the market and other investors about 322 million pounds in extra fees paid to Qatar, disguised as "bogus" advisory services agreements (ASAs).

Jenkins, the former head of Barclays' Middle East business, Tom Kalaris, who ran its wealth division, and Richard Boath, a former head of European financial institutions, deny conspiring to commit fraud and fraud by false representation, each carrying a maximum 10-year sentence.

Jenkins, once known as the "gatekeeper to Qatar" because of his close personal relationship with Qatar's former prime minister Sheikh Hamad bin Jassim bin Jabr al-Thani, said the ASAs were approved by lawyers and designed to provide value for Barclays as an investment for genuine services.

"Value is the umbrella that covers services, advice, introduction, deal flow -- it is that which I hang my hat on," he told the jury.

Asked why Gay Huey Evans, a former Barclays manager tasked with building relationships with sovereign wealth funds in 2008, did not know about deals for additional services from Qatar, Jenkins said her evidence was "very surprising".

But he said he had been too busy to "tick boxes" to check how the investment under the ASAs was being monetised during the febrile atmosphere in 2008, when executives stood to lose their bonuses and jobs and banks stood on the brink of collapse.

"I'm sorry I did not tick the boxes and deal with this. It was done later," he said.

By Kirstin Ridley