Bets worth more than €20,000 closely matched entries in a notebook found in the prison cell of criminal Brian Rattigan, a court was told.
Paddy Power internal audit manager Gerard Melinn told Sean Guerin, prosecuting, that he conducted an analysis to determine if bets recorded on the bookmaker's computer system matched those recorded in a notebook seized in Portlaoise Prison on May 22, 2008.
The Special Criminal Court previously heard evidence that one of two notebooks seized from the cell was a "very detailed" diary of betting activity, recording details of various English football matches.
Detective Garda Shane Curtis told the court it was his belief that the notebooks also contained what are commonly known as "tick lists", detailing peoples' names and weights of drugs.
Mr Melinn said that he identified 52 potential matches between the notebook and the Paddy Power internal system, of which 15 were potential "Dial-a-bet" transactions from telephone accounts and 37 were potential anonymously placed retail betting transactions.
He told the court that account details for telephone betting accounts in the names of Patrick McEnroe and Richard Rattigan were recorded in the notebook and that he also analysed the transactions on these accounts.
Mr Melinn said that of the 52 potential matched bets, which were all placed between September 2007 and May 2008, 35 reconciled with the details of the bets recorded in the notebook precisely, while a further 13 matched the details to within 90pc.
Rattigan (32), formerly of Cooley Road, Drimnagh, denies possessing heroin for sale or supply on May 21, 2008.
He also denies possessing two mobile phones inside Portlaoise prison while an inmate on May 22, 2008. The prosecution claims Rattigan used mobile phones to act as the "directing force" behind a €1m heroin deal from his jail cell.
The trial continues.