The Moriarty Tribunal will switch its spotlight from former Taoiseach Charles Haughey to the Tipperary north TD Michael Lowry today.
The inquiry is probing the financial relationship between Mr Lowry and businessman Denis O’Brien.
Specifically, the tribunal legal team are to examine four payments totalling £500,000, which appears to link Mr Lowry and Denis O’Brien.
In a statement yesterday, Mr Lowry denied receiving payments either directly or indirectly from the former Esat boss.
The payments outlined already by the tribunal relate to a £33,000 donation to Fine Gael and three other transactions relating to properties in Dublin, the UK and Spain.
When Mr Lowry takes the stand, he will be questioned about his relationship with Mr O’Brien and his granting of a mobile phone licence to Esat Digifone while he was the Minister for Communications in 1995.
Mr O’Brien made £230m when Esat was sold last year.