Treasury Holdings has provided the Flood tribunal with details of a payment it made to Fianna Fáil Senator Don Lydon. The company confirmed yesterday that it made what it termed a "political donation" of £1,000 (€1,270) to Mr Lydon in May 1999. It declined to comment further on the cheque which was disclosed by Mr Lydon in his annual return to the Public Offices Commission.

The payment was made by a company called Castlemarket Holdings that was controlled by Mr John Ronan and Mr Richard Barrett, the principles of Treasury Holdings. At the time Castlemarket was seeking planning permission to redevelop Stillorgan Shopping Centre in South Dublin.

Mr Lydon was a member of Dún Laoghaire Rathdown County Council which had previous granted planning permission to Castlemarket, only for it to be overturned by An Bord Pleanála.

The subsequent application by Castlemarket was successful, but again was turned down on appeal by An Bord Pleanála. A third application to develop the shopping centre was approved in recent weeks by the council, but it is expected that it will also be appealed to An Bord Pleanála by local residents.

Castlemarket - which was a joint venture between Treasury and Jermyn Properties of the UK - is also behind a €600 million plus office development near Leopardstown, Co Dublin. The company was subsequently absorbed into Real Estate Opportunities, a quoted investment company floated by Treasury and Aberdeen Asset management in June 2001.

Mr Lydon has emerged as a central figure in a bribery allegation being investigated by the Flood tribunal into planning corruption. The political lobbyist Mr Frank Dunlop has told the tribunal that Mr Lydon sought a £5,000 bribe in return for supporting a rezoning proposal. Mr Dunlop alleges that he ultimately paid Mr Lydon £3,000 in 1992 in return for his signature on a motion to rezone 106 acres of land at Carrickmines in south Dublin.

Mr Lydon has declined to comment after taking legal advice. In a statement issued through his solicitors he said that he expects to emerge from the tribunal with his "personal and political integrity fully intact."

Mr Dunlop was a consultant to Treasury Holdings until last year when he was called to testify at the Flood tribunal. The former Government press secretary gave the tribunal details of various "bribes" he alleges he made to county councillors in return for their support for rezonings.

Treasury Holdings is one of the largest and most successful property development companies in the State.