An Oireachtas watchdog last night ruled there were no grounds for an inquiry into the awarding of a public relations contract to consultant Ms Monica Leech by the Minister for Transport, Mr Cullen.
The Standards in Public Office Commission revealed it had considered the matter and felt no need to examine the awarding of contracts to Waterford-based Ms Leech.
The ethics committee ruled that the evidence before it did not establish a prima faciecase warranting an investigation within the terms of the relevant legislation.
In a statement following the watchdog's verdict Mr Cullen said: "I note this evening's announcement that the Standards in Public Office Commission, having considered the matter, has found that there are no grounds for an investigation.
"Taken together with the Quigley inquiry, all matters relating to this issue have been comprehensively examined by independent persons. I look forward to continuing to work hard in my role as Minister for Transport and to delivering on the many challenging and exciting policy initiatives under my responsibility."
Ms Leech first worked for Mr Cullen when he was Minister for State at the Office of Public Works. She again secured a contract as external public relations consultant on a single tender basis when Mr Cullen became the Minister for Environment in 2002.
Ms Leech held on to the post when it was opened up to competing bids. Mr Dermot Quigley, former chairman of the revenue commissioners, also investigated the awarding of contracts to Ms Leech. No evidence of any impropriety was found.
Mr Cullen claimed that Mr Quigley's 45-page report exonerated him. The Quigley report raised a number of concerns including how the contracts were advertised and the monitoring of the work. It concluded that this could have given rise to a perception of impropriety.
The Government last week said it had ended its working relationship with Ms Leech who has been paid more than €300,000 for her work.