A lawsuit filed against former Irish Taxation Institute president Noel Corcoran by a US firm he once chaired has been dismissed as "totally without foundation" by his legal representatives.

It emerged earlier this week that the tax adviser, whose high profile clients include Sir Anthony O'Reilly, has been sued by North Carolina-based biofuels company NewGen on charges of fraud, negligent misrepresentation, civil conspiracy and intimidatory behaviour.

In a statement issued on his behalf yesterday, Mr Corcoran's US law firm said that he will be "vigorously" defending himself against these accusations.

Mr Corcoran believes that the lawsuit is a "defensive tactic" by NewGen to delay the repayment of loans he made to the firm which he claims are overdue, and to avoid the consequences of its failure to honour a letter of intent to sell certain assets to him.

The law firm said that a formal response to NewGen's lawsuit will be filed shortly, and will dispute all of the major allegations levelled against their client.

Furthermore, Mr Corcoran intends to file a counter claim against the company based on the issues of the loans and the letter of intent, according to Richard Lanzillo, senior partner of Knox McLaughlin Gornall & Sennett, based in Erie, Pennsylvania.

"Our client has done nothing wrong," said Mr Lanzillo. "Indeed, his prior financial and management support for the company is a primary reason the company remains in operation," he said. Mr Corcoran joined the board of NewGen in January 2006 and became chairman in May of that year.

During his time as chairman, he negotiated the acquisition of the Tennessee-based chain of petrol stations, Appalachian Oil. However, the deal fell through due to NewGen's inability to raise the purchase price.

The failure of this acquisition and Mr Corcoran's relations with other board members are the subject of the current lawsuit.