A former Barclays chairman has said he was unaware of documents detailing £280m worth of payments to the bank’s Qatari investors in 2008 that is at the centre of a fraud trial in London.

Lead prosecutors for the Serious Fraud Office (SFO) questioned Marcus Agius over his knowledge of a key document from 31 October that year, detailing the payment terms of an advisory services agreement that would result in the bank paying £280m to the Qataris.

“Absolutely not … I saw this document for the first time some years afterward,” Agius told a jury at Southwark crown court on Wednesday. “Not only did I not see this document, I was not aware of its existence.”

The SFO’s lead prosecutor, Edward Brown QC, went on to ask whether the former chairman was aware of how it was negotiated or how the figure was arrived at. To both questions, Agius answered “no”.

The SFO alleges four former Barclays executives – Richard Boath, John Varley, Roger Jenkins and Tom Kalaris – lied to the stock market and other investors about how £322m in fees were paid to Qatar in relation to emergency fundraising of more than £11bn in 2008.

Prosecutors say the executives put together two advisory services agreements in order to disguise Qatar’s demand for larger commission payments.

All four men have denied the charges. Prosecutors have not accused Agius of wrongdoing.

On Tuesday, the former chairman was asked what his reaction would have been if he was told of additional fees paid during the fundraising.

Agius said he would want to understand why they were necessary, as it would have been an “exceptional move” and that everyone should be “paid the same”. He added that fees for one set of underwriters and not another “would be completely contrary to market practice” and “undermine the entire project”.

On Wednesday, Agius told the court tthere was some disappointment over how surprised the market was that Barclays was pursuing a second round of emergency funding as the financial crisis reached a peak in October 2008.

He said it was disappointing to see the share price reaction, “despite the fact that market testing” showed support for financing. “It’s also true to say that the absence of the ability of small shareholders to take up pre-emptive rights was the subject of some disappointment,” he added.

After Agius completed his witness testimony on Wednesday morning , the prosecution presented further documents and emails spanning the period into late 2010.

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The jury was read an an email sent in January 2010 by Peter Estlin, who served as the group’s financial controller for two years from 2008. The message he sent to a member of the Barclays finance department relayed questions from the auditors PricewaterhouseCoopers about the Qatari advisory services agreement.

Estlin said: “[PwC] were eager to understand that there is real activity supporting the payments, even if they are expensive.” He added that there was a need to “understand the meeting, introductions, etc that they assisted with”.

The trial, which is expected to last up to six months, continues.