Gardaí have confirmed an investigation is under way into the circumstances surrounding the disclosure of a confidential Government document to a friend of the Tánaiste almost two years ago.

Leo Varadkar told the Dáil he gave a copy of an agreement between the State and the Irish Medical Organisation to Maitiú Ó Túathail, the then president of a rival GP organisation, the National Association of General Practitioners in April 2019.

The garda investigation, which has now been upgraded from an initial scoping exercise, will determine the facts surrounding the incident and gather evidence for a file to be submitted to the Director of Public Prosecutions.

The DPP will decide whether or not any laws may have been broken and whether or not criminal charges are to be preferred.

The investigation is being carried out by the National Bureau of Criminal Investigation, which is under the overall command of Assistant Commissioner John O' Driscoll, the head of organised and serious crime.

A team of detectives has been appointed to the investigation, which is being led by a senior officer.

The investigation is focused on potential breaches of existing legislation, such as the Official Secrets Act or the Criminal Justice Acts.

Gardaí have already received statements from a number of people, including the Minister for Higher Education Simon Harris, who was minister for health at the time.

A spokesperson for Mr Varadkar said today: "The gardaí have not been in contact with the Tánaiste about this matter.

"Last month, on foot of media reports, his solicitors contacted the gardaí to confirm his willingness to meet them and provide a statement.

"His legal advice is that he has committed no offence and looks forward to the matter being concluded."

Garda Headquarters said today it does not comment on ongoing investigations.

When asked if Mr Varadkar should stand aside, without prejudice, from his position at Cabinet while gardaí investigate the matter, Minister for Social Protection Heather Humphreys said: "Absolutely not."

Speaking on RTÉ's The Week in Politics, she added: "The Tánaiste made his position very clear in the Dáil last November. He said it was an error of judgement.

"What he did was in the interest of GPs, patients and the general public. He had nothing to gain from sharing that document."

Speaking on the same programme, Sinn Féin's Mairead Farrell said it was her party who put down a motion of no confidence in Mr Varadkar in November.

"It is absolutely wrong and very, very clear that that type of culture has no place in our society," she said.

Minister for Public Expenditure Michael McGrath has said Mr Varadkar was entitled to due process and it was important that the integrity of the investigation was protected.

When asked on RTÉ's This Week programme if Mr Varadkar should stand aside during the investigation, he said: "I don't believe that that is necessary.

"The gardaí should be given the time and space to work through this investigation in the normal way. None of us know how long such an investigation might take and how long it might take then for an eventual decision to be made."

He said that Fianna Fáil had full confidence in the Tánaiste.

Additional reporting Mary Regan