Former Fine Gael senator Mr Liam Cosgrave failed to declare a payment of £2,500 from Mr Frank Dunlop to the Public Offices Commission in 1998, the Flood tribunal heard today.
Mr Cosgrave who was running as a candidate for the Seanad at the time said he had forgotten about the payment when he made his declaration six months after receiving it.
He said he received the payment from Mr Dunlop as a political contribution towards his campaign.
The former senator was reminded by counsel for the tribunal, Mr John Gallagher, that it was a criminal offence to make a false declaration to the Commission.
Under Electoral Act of 1997, all donations over £500 had to be declared to the Public Offices Commission. Mr Cosgrave said he deposited £500 into his bank account and kept £2,000 in cash.
Earlier, Mr Cosgrave told the tribunal he never canvassed fellow Fine Gael councillors to vote for certain planning motions during his time on Dublin County Council.
He said that although Fine Gael members met to discuss certain planning issues, there was never a party whip and different councillors had different views.
In his second day of evidence to the tribunal, he said the only vote he could "deliver" on any motion was his own.
Mr Cosgrave is one of nine councilllors accused by former lobbyist Mr Frank Dunlop of accepting payoffs in connection with the rezoning of land at Carrickmines, south county Dublin.
Mr Cosgrave denies the allegations.
When asked by Mr Gallagher if he knew of allegations of planning corruption in Dublin the 1980s and 1990s, Mr Cosgrave replied he "was aware" of such claims.
However, in his view, "all councillors did the best for their areas and worked hard," he said.
Yesterday, Mr Cosgrave told the tribunal he kept no records until recently of expenses incurred and donations received during his 22-year political career.
