A former treasury risk manager at Anglo Irish Bank has told a jury at the Circuit Criminal Court that the €7.2 billion transaction at the centre of David Drumm's trial did not go through the usual credit approval process.

Michael Nurse, who was a treasury risk manager, was outlining the process used by the bank's risk committees for approving transactions.

David Drumm, 51, from Skerries in Co Dublin, has pleaded not guilty to conspiracy to defraud, by engaging in transactions between Anglo, Irish Life and Permanent and Irish Life Assurance to mislead depositors, investors and lenders about the true value of deposits to Anglo between March and September 2008.

Mr Nurse told the jury the treasury credit committee met weekly to approve bank credit limits.

After analysis, limits would have to be signed off by four managers - two senior and two more junior.

However, there was also a fast-track process designed to respond more quickly to a request rather than wait for a weekly meeting.

These requests required only one senior management signature and would go to the next credit committee for ratification.

He told the jury a €1bn transaction with IL&P in March 2008 had been fast-tracked. That transaction had exceeded the credit limit by 400%.

Asked if the €7.2bn transaction later that year went through the same process, Mr Nurse said it had not.

Instead, it had been dealt with at an executive management level and his signature was not required.

He said he approved it "post transaction" after he signed off on a credit excess report generated the day after the transaction.

He said: "Essentially, the team performing that transaction were dealing with the Chief Executive (David Drumm) and the Chief Financial Officer Willie McAteer, who was also chief risk officer."

He said he became aware of the transaction either the same day or the day after it happened.

The exposure was €7.2bn. He said he and Mr McAteer signed off on it in a "retrospective sign off".

Asked if this was common practice, he said "no".