U2 star Adam Clayton has begun giving evidence against his former personal assistant accused of embezzling 2.8 million euro of his funds.

Taking to the stand, the bassist joked he was not used to being in front of a microphone.

"I'm more of a 'dum, dum, dum', but I will practise my technique," said the musician, who has been a member of U2 for 30 years.

His former PA, Carol Hawkins, is on trial for stealing cheques from the bassist over a four-year-period.

The 48-year-old worked for Clayton for 16 years from 1992.

The mother-of-two listened attentively as Clayton, dressed in a navy jacket and grey shirt, was grilled on their working relationship and details of his bank account.

The defendant was a signatory on two of his accounts.

It was from these accounts that Ms Hawkins stands accused of drawing 181 cheques and lodging them into her own bank and financing a lavish lifestyle.

Prosecution barrister, senior counsel Colm O'Briain, previously told the Circuit Criminal Court in Dublin that Ms Hawkins lodged the money into her own personal account, a joint account with her then husband John Hawkins and a credit card account, between 2004 and 2008.

Ms Hawkins, from Lower Rathmines Road in Dublin, denies all the charges.