An employee of the Bank of Ireland has been arrested and is being questioned by gardaí investigating the biggest bank robbery in the history of the State.

Over €7m was taken after a gang forced a bank official to go into the College Green branch of the bank in Dublin and take out the cash on 27 February last year.

The gang held the bank official's girlfriend, her mother and six-year-old nephew hostage until the money was handed over.

A man in his 20s was arrested yesterday and is being detained at Naas Garda Station.