Gardai have quizzed the artist behind the nude portraits of Taoiseach Brian Cowen.

Bolton Street teacher Conor Casby presented himself at Pearse Street Garda station where he was interviewed last night.

Hours earlier detectives threatened to raid Today FM’s offices after Mr Casby contacted the Ray D’Arcy show.

Gardai said they would get a search warrant for the show’s studios unless they handed over the artist’s contact details.

The nude paintings have already caused a furious row between RTE and the government.

The station issued a grovelling apology last night for a frivolous story on the paintings and said sorry for any hurt caused to Mr Cowen and his family.

“The RTE coverage of the affair could have been interpreted as trying to embarrass the Taoiseach,” a Minister told the Herald today.

“The story has been picked up by the international press since RTE covered it; that’s the last thing the country needs,” the Cabinet minister added.

Two men are believed to be behind the prank, which saw the naked portraits of Mr Cowen placed simultaneously in the National Gallery and the Royal Hibernian Academy.

However, Mr Casby has stated that he was not the prankster behind the placing of the paintings in the galleries.

Gardai suspect that Mr Casby, who says he is the artist responsible for the nudes, may have painted more unflattering pictures of the Taoiseach and other leading politicians.

The garda investigation was launched as the story gained coverage in British, American and Australian newspapers.

A source said: “This may have started as a prank, but it’s now a national embarrassment. A full investigation is under way.”

The garda probe into the matter began yesterday when officers called to Today FM’s Digges Lane offices and spoke to staff at the Ray D’Arcy Show to get contact details for Mr Casby.

The officers claimed that hanging up the nude images could be deemed illegal under incitement to hatred, indecency and criminal damage legislation. They asked for his email address and phone number.

“We said no and they said they may need to get a (search) warrant,” Mr D’Arcy said.

Meanwhile, the Government Press Secretary today said that they had not complained about RTE’s decision to cover the story. The objection was merely to the manner in which the story was portrayed and presented.

Mr Cowen’s press secretary also revealed that he had not sought the apology which was broadcast on the Nine O’Clock News last night.

A statement was read, noting: “RTE News would like to apologise for any personal offence caused to Mr Cowen or his family and for any disrespect shown to the office of the Taoiseach by our broadcast.”

Meanwhile, Mr Cowen will be relieved that his naked portrait is unlikely to ever see the light of day again.

The two unflattering paintings are now to become dust collectors.

Despite creating huge public interest, the paintings will not be given a permanent place in the gallery where they were first hung, and will instead by consigned to the archives or destroyed.

“We’re the National Gallery, housing Irish and European art works that are either gifted, purchased or specially commissioned.

“That’s the only way they can appear in the gallery,” explained a spokesperson.

She added that they have a “very, very careful selection process”.