Sean Quinn's hotel group made profits of €9.2m (£6.26m) in 2005, even though it includes just two of the Fermanagh billionaire's nine hotels.
Mr Quinn's more high-profile hotel interests include the Belfry near Birmingham and the Slieve Russell in Co Cavan, but the only hotels in Quinn Group Hotels Ltd are the Hilton and Ibis in Prague.
These two hotels notched up a turnover of €48.3m (£32.9m) in 2005, down slightly on 2004's figures of €49.8m (£33.9m), while profits fell from €11m (£7.4m) to €9.2m (£6.2m).
A spokesperson said the fall in profits and turnover was due to refurbishments which had taken place over 2005. The accounts which have just been filed were several months overdue, and the 2006 accounts are due in the coming week.
The spokesperson said he could not comment on whether this downward trend was reversed in 2006. " You'll just have to wait and look at the accounts," he said.
At the end of 2005, the Prague hotels were valued at €166m (£113m), while net assets were almost €20.8m (£14.1m).
Mr Quinn's hotel portfolio is split between Ireland, the UK and eastern Europe.
Dublin's Buswells Hotel and the Slieve Russell Hotel, Golf and Country Club make up the Irish portfolio.
Mr Quinn is one of Ireland's richest men with an empire that spans healthcare, financial services, property and hotels.