The Taoiseach has denied any wrong-doing in relation to the purchase by the state of the Battle of the Boyne site in Co Meath.
The historical site was bought from a group of investors last year for £7.8m. This amount was £5m more than the price of the site in 1997.
One of the businessmen involved, Tim Collins, is a former treasurer of the Taoiseach’s constituency office in Dublin.
Mr Ahen has told the Dail he knew nothing about his involvement until after the sale.