The Taoiseach has insisted that a criminal complaint of harassment made by a Cabinet minister against a blogger is a private matter.

Leo Varadkar’s comments in the Dáil marked the first confirmation of the exact nature of a complaint made by the Social Protection Minster Regina Doherty.

It emerged last week that New-York based blogger, Catherine Kelly had been stopped and cautioned at Dublin Airport about comments she had made regarding Minister Doherty.

The caution related to a blog post, written in April, in which she had questioned the minister’s business dealings regarding a bankrupt company in 2009.

The revelations led to accusations that the minister was attempting to use the gardaí as her own personal police – with Solidarity TD Ruth Coppinger saying the involvement of the gardaí in the dispute was “sinister.”

She said Ms Kelly had undergone a “chilling experience” at the airport – adding that she was stopped by two plain clothes gardaí who questioned her about her social media use and whether she had written an article about the minister.

She said she was cautioned not to tweet Minister Doherty or any material relating to her.

"Is it now Government policy to attack anybody who criticises anyone in the Government on social media in this very sinister way?" she asked.

In the Dáil this evening, Sinn Féin deputy leader Mary Lou McDonald questioned the Taoiseach on what she said was “a very strange and very serious allegation” against Minister Doherty.

Mr Varadkar said the complaint was a personal issue that had nothing to do with the government.

“I had a brief conversation with her about it,” he said. “I understand that she made a complaint to the gardaí with regard to harassment and the gardaí thought it sufficient to caution the individual against whom the complaint was made.”

“But obviously if you have any further questions I think you should put them to her directly. This is clearly a private matter.”

“It is not one of public policy; it is one involving two individuals.

“One individual who felt that she was being harassed by another and the gardaí - based on the evidence that they saw - decided to take the action that they did.”

Ms Kelly is reportedly considering legal options regarding her experience.