Independent News & Media (IN&M) chief operating officer Gavin O'Reilly has claimed that the questioning of its governance by Denis O'Brien is designed to weaken its share price in advance of a bid for the business from the telecoms billionaire.

Mr O'Brien's spokesman would not say whether he planned a bid but said his IN&M investment was strategic and cited previous investments in media and communications. He stressed IN&M was a long-term investment for Mr O'Brien and rejected the assertion that he was trying to weaken it.

Mr O'Brien has said he will return to the governance issues raised in letters he sent to IN&M in light of what he said were incomplete responses from that quarter. IN&M, which gave the correspondence to The Irish Times yesterday, disputes Mr O'Brien's interpretation in strong terms.

One letter says IN&M insists chief executive Sir Anthony O'Reilly flies on a Gulfstream IV private jet at all times for security reasons. A spokesman said this was in line with the practice of other multinational organisations and said Sir Anthony was personally billed for using the aircraft whenever he did not travel on company business.

After an annual meeting on Wednesday at which IN&M defended its governance, Mr O'Reilly questioned Mr O'Brien's motivations in publishing a report on its governance and in his letters to IN&M.

"The whole tenor of the letters, the whole tenor of the report is designed to destabilise the company. The report was calculated to cause damage to IN&M and its shareholders," he said.

"You could speculate that these letters are designed to damage the company, impugn the directors and drive the share price down so he can make a bid for the company. It's hard to draw any other conclusion."

Mr O'Brien's spokesman said: "Obviously, asking reasonable questions is an unreasonable act in the manner in which the O'Reilly family run IN&M."

Mr O'Reilly said Mr O'Brien was positioning himself as "the self-proclaimed poster child" of good corporate governance.

"He bought 3.01 per cent [ of IN&M] in January last year and made a voluntarily disclosure, much in the manner he did with Aer Lingus as well. Over this time, he was presumably having sleepless nights worrying about corporate governance in IN&M and then he buys more of the company."