LEO VARADKAR has called for an official probe into Sinn Féin's finances after accusing the party of illegal political funding.
The Fine Gael leader said that some Sinn Féin politicians "appear to live way beyond their means" before calling for an investigation into their finances.
It's understood Sinn Féin's shadowy financial profile is one of the key reasons why Varadkar and Fianna Fail leader Michael Martin are so reluctant to deal with Mary Lou McDonald's party.
Writing in the Sunday Independent, Varadkar said: "Sinn Féin public representatives claim to earn only the average industrial wage, yet their salaries are not returned to taxpayers or donated to the party."
"Many appear to live way beyond their means," he added.
The acting Taoiseach also stressed that "irregularities" in the party's political fundraising warranted scrutiny from authorities, insisting that the stories of how the party was funded were a "real concern".
Varadkar claimed that "lavish" fundraising events in America were held by Sinn Féin and money was then "routed through Northern Ireland".
He also claimed that the party bought office space using "front companies" and said Sinn Féin MPs collected £4.5m from Westminster without taking their seats.
"These irregularities cause us real concern and deserve further scrutiny and a proper investigation. Sinn Féin owes it to all of us to clear up these matters once and for all," he added.
A Sinn Féin spokesperson said on Sunday that Mr Varadkar's comments were a "disgrace" and beneath the office of the Taoiseach.
"These comments are completely fabricated and this is outrageous mud-slinging on the part of the caretaker Taoiseach who is clearly struggling to get to grips with the election results and this weekend's opinion poll," he said.
"These disgraceful and baseless comments discredit the office of Taoiseach and Leo Varadkar really should reflect on them."