Bookmaker Paddypower has admitted it made a mistake, after paying out more than €80,000 in bets on a Yes vote in the Lisbon Treaty referendum.
As polls closed at last night, the bookmaker made a decision to pay out punters who had backed a Yes vote after unofficial exit polls indicated a late surge in support for the treaty.
The blunder means the bookmaker will be forced to pay out over €180,000 in referendum bets.
In a statement, Paddy Power said: "Last night, there were rumours of an exit poll showing the Yes side in the lead and all the late betting suggested a swing in support for the treaty."
"It's an unlucky Friday 13th for Paddy Power but a lucky one for our punters," it added.