Mr Liam Lawlor's evidence to Mahon tribunal could be about to land him in serious trouble if it decides he lied under oath.
The tribunal chairman, Judge Alan Mahon, said he and his two colleagues would be considering over the next six weeks whether or not to send a file to the Director of Public Prosecutions with a view to pursuing a criminal case.
He said the tribunal was "particularly concerned" at certain elements of Mr Lawlor's evidence under oath during his ten days in the witness box this month.
Mr Lawlor has admitted he was given an under-the-counter payment of £100,000 sterling following the sale of an acre of land beside his home at Somerton, Lucan, Co Dublin in November 2001.
The developer who bought the land, Mr Michael Whelan of Maplewood Homes, told the tribunal the former Fianna Fáil TD had originally sought £200,000 sterling in cash "under the table" on top of the asking price of £625,000.
They finally settled for a cheque for £100,000, which was paid last September into a client account in Seddons, Mr Lawlor's legal firm in London and Prague. Mr Lawlor subsequently issued Mr Whelan an invoice for £17,000 for VAT on the payment.
Mr Whelan's account differed markedly from Mr Lawlor's version, in which he claimed the money was paid to him as fees for discovering a property for development in Piccadilly in central London.
But there was "no way", Mr Whelan said, that he would ever pay anyone that much money for discovering a property and, in any case, Mr Lawlor had never given him advice on property in England.
Judge Alan Mahon refused to accept Mr Lawlor's explanation, saying it was a "sham" to cover up the £100,000 payment, adding that Mr Lawlor was defrauding the Revenue by not disclosing the extra cash.
Mr Lawlor admitted that no tax has been paid on the payment, but the matter is being dealt with at the moment in talks with the Revenue Commissioners.
