The artist behind nude paintings of Taoiseach Brian Cowen which were hung in two public galleries could face criminal charges, it was revealed today.

The 35-year-old school teacher, named as Conor Casby, was tracked down to his south Dublin home after investigators scoured CCTV footage of the prank.

The furore over the incident forced RTE to apologise about its coverage after a complaint from a Government official, while a detective called yesterday at the studios of Today FM to demand details of email contacts with the artist.

A Garda source revealed that Casby was not arrested but voluntarily accompanied investigators to Pearse Street Garda Station in central Dublin yesterday to be interviewed.

A file is being prepared, which could be sent to the Director of Public Prosecutions.