One of the country's largest bookmakers is refusing to pay out on a ticket worth more than €5,200 after claiming that the €20 wager which it accepted from a punter was in fact placed late.

Chinese national Xin Yu (Jack) Guo bought a ticket for Ladbrokes' "49's teatime 7-number draw" at its branch in Drimnagh, Dublin just over three years ago.

Speaking through his wife, Guo – who for family reasons was unable to go public with his case until now – said he had received a ticket from the cashier acknowledging that he had entered the draw on that day.

A copy of the ticket has a time print of 16.13.58 on the 15/12/06, along with the name of the cashier who accepted the bet. It appears to show three winning numbers -13,24 and 46 –for which a prize of €5,265 was payable.

However, when Guo went to claim his prize, he was amazed to be informed that his bet, although accepted by the company for the draw, was in fact placed late. As a result, it was void as the draw had taken place just a few minutes earlier.

The company has since maintained that when he presented his ticket it was scanned and this indicated that it was two minutes and two seconds late for the draw. Crucially, this only becomes apparent when the "winning" ticket is put through its computer system for the relevant draw.

"I would have understood if there was an announcement saying "no more bets" before I placed the bet, as is supposed to happen. But there was none. I had no way of knowing when I was betting that my bet was late," Guo told the Sunday Tribune. "It's the principle... when we lose, they keep the money, but it's not fair that when we win they also keep the money."

Guo's solicitor, William Devine of Byrne Wallace, called on Ladbrokes to honour all bets once they have accepted them.

"Staff should know when it is too late to place a bet. If it is close to the time of the event in which the customer is interested (race, lottery etc.) then they should check if it is too late to accept a bet, rather than accepting it and telling the customer, if he wins, that he was too late," he said. "The bookmaker should not accept bets which are not going to be honoured."

A spokesman for Ladbrokes refused to say why it takes bets from customers on events which may already have taken place, or why it does not have a computer system in place to ensure such bets are not accepted by staff.

He said the case had been referred to the Independent Betting Adjudication Service (IBAS), which adjudicates on disputes that arise between betting operators and their customers.

"The IBAS considered this case fully, and received detailed information from all parties in the matter," he said. "IBAS found in favour of Ladbrokes following the consideration of all of the information in this matter."

However, Devine said neither he nor his client had provided any information to the IBAS, and had not been contacted to participate in any adjudication process.