The former business editor of the Sunday Business Post, Tom Lyons, has told the High Court the newspaper published details of a confidential Government report into Irish banks because it was an incredibly serious story, which was in the public interest.

Mr Lyons was giving evidence in the defamation action being taken against the newspaper by businessman Denis O'Brien.

Mr O'Brien claims the reports published in March 2015 portrayed him as one of a "gang of 22" "developer kings" who over borrowed, destroyed the country and bankrupted the banks. 

The Sunday Business Post says the articles do not have the meanings claimed by Mr O'Brien.

Mr O'Brien's evidence finished this afternoon and Mr Lyons began his evidence in the newspaper's defence.

Mr Lyons said a decision was taken to publish details of a report by PwC into Ireland's banks because it showed, for the first time, how the banks misled the Government about the scale of their problems. 

He said it was an extraordinary period of time in Irish life and the Irish public deserved answers.

The report was given to the Government in November 2008, after the banks had been guaranteed.

He said the impression given by the banks to PwC was "woefully optimistic" and the worst case scenario was that they might suffer losses of more than €10 billion - that turned out to be €64 billion.

Mr Lyons said the banking inquiry was underway at the time of the publication - an inquiry that was supposed to get answers for people. He suspected the inquiry had not been given the report and they later approached the newspaper looking for a copy.

Mr Lyons said he had the report for a couple of months and worked on it intensely for about five or six weeks.  When he first read it, he thought it was astounding and that it was in the public interest that people know about it.

He told the court they were being anything but voyeuristic about people's banking affairs. The newspaper took the story incredibly seriously he said and wanted to get it right.

Mr Lyons said they had named the 22 people, because they felt this demonstrated the risks the banks were taking by lending too much money to too few people. 

He said the 22 names and the order in which they were listed came from the PwC report. And it was totally ludicrous to suggest he would have inserted someone into the list for some bizarre reason.

Mr Lyons rejected a suggestion that the story was already in the public domain. He said a previous story he had written for the Sunday Independent, dealt only with borrowings from Anglo. He said no other report had aggregated Denis O'Brien's borrowings across the banks. And he said it was untrue to suggest this had all been in the public domain before and was ‘old hat’.

He also rejected suggestions from Mr O'Brien that the newspaper's editor Ian Kehoe may not have been in the office and had let him go off on a solo run. He said Mr Kehoe went through the report line by line, checking every sentence.

He said the editor was prudent and careful and wanted to ensure everything they wrote reflected the report accurately. He said the articles had also been seen by a solicitor and a barrister. The newspaper felt they were fair and in the public interest to publish.

Mr Lyons said he generally agreed that everyone was entitled to privacy. But he said the articles were not talking about Mr O'Brien's credit card details or whether he was paying for Netflix or Sky. 

He said these were big picture numbers contained in a report paid for by the taxpayer, and used by the Government to inform major decisions.

He said it would have been unfair to leave Mr O'Brien out. He told the jury that there had been a "fear factor" and a debate in the office about leaving his name out because he was a major employer of journalists and also because he sued a lot of journalists.

But he said they had to put those fears aside. Mr Lyons said Mr O'Brien was included because he was on the list and they faithfully reported the report.

Mr Lyons said he believed Mr O'Brien to be someone who was in strong financial shape in 2015 and it was ridiculous to suggest that he had brought down the country. 

He said he wanted to give everyone profiled roughly the same amount of words and to convey that Mr O'Brien was one of a number of "good guys" in the list of 22. 

He agreed Mr O'Brien was a successful businessman but what was disturbing about his borrowings was that he owed most of his €1 billion euro in loans, to Anglo Irish Bank, the "world's worst bank". 

And it was disturbing anyone had such a large exposure to this bank. He said in 2008, if a liquidator had come in, instead of the Government propping up the banks, everyone would have had to repay their loans at once, and the country would have ground to a halt.

Mr Lyons claimed a headline on the front page referring to the files "they don't want you to see" was implying that the Government did not want people to see the report.

He will continue his evidence tomorrow.