Nicholas "Nick" Di Girolamo is suing the publisher of The Sydney Morning Herald for damages, claiming his reputation has been "completely destroyed" by the articles.

Fairfax Media is defending the case. It says the articles are not defamatory but, if they are found to have defamed Mr Di Girolamo, it has the defence of truth, contextual truth and/or qualified privilege.

In the NSW Supreme Court on Monday, the jury of four women were told the six articles were published between December 2012 and August 2013 and were written by Herald reporters Kate McClymont and Sean Nicholls, as well as Linton Besser, who now works at the ABC.

As well as damages and costs, Mr Di Girolamo wants the articles permanently removed from Fairfax Media websites.

In his opening address, Mr Di Girolamo's barrister Bruce McClintock, SC, said the allegations against his client were "right at the top of the scale: corruption and in effect bribery of a cabinet minister".

Mr McClintock accused Fairfax Media of a "smear campaign over months to destroy my client's reputation".

Mr Di Girolamo claims the first article, headlined "Costa, Obeid and the water firm", published on December 15, 2012, was defamatory because it imputed he engaged in corrupt conduct by promising former NSW treasurer Michael Costa $3.75 million in shares in Australian Water Holdings in exchange for Mr Costa using his position to block a public tender.

Mr McClintock told the jury to "forget" anything they knew about the Independent Commission Against Corruption investigations into AWH or any of the key players at the time the articles were published and since then.

He said they might have heard Mr Di Girolamo's name linked to the resignation of former Liberal premier Barry O'Farrell in April 2014, but he said: "It's got nothing to do with this case.

"Simply because something was said at ICAC or decided by ICAC, it shouldn't affect your decision."

The court heard a roll-call of former premiers might be called to give evidence, including Kristina Keneally, Nathan Rees and Morris Iemma. Other current or former politicians who will be mentioned or called include federal frontbencher Arthur Sinodinos, former state minister Eddie Obeid snr, former planning minister Frank Sartor and former NSW Labor premier Bob Carr. Several of Mr Obeid's sons, including Moses Obeid, will also be mentioned.

Veteran Wests Tigers player Robbie Farah will be a character witness for Mr Di Girolamo, as, for a time, Mr Di Girolamo was on the club's board. Mr Di Girolamo will not be called to give evidence in his case.

Mr McClintock said "the name Obeid – in the eyes of the SMH – has become synonymous with corruption".

"The mention of his name carries a flavour of corruption but this case is not about him.

"Nick Di Girolamo worked in the same business as one of his sons and what's wrong with that?" Mr McClintock said.

He said that, while ICAC found Eddie Obeid snr engaged in corrupt conduct, he had not been found guilty of a criminal offence.

In relation to one article, headlined "Water company donated cash to Nationals MP", Fairfax Media is also arguing the defence of fair comment or honest opinion.

Mr Di Girolamo claims the article, published on March 19, 2013, imputed he caused a cash donation of $10,000 to be made to Nationals MP Katrina Hodgkinson to influence future decisions made by her as a member of Parliament.

He also alleges the article defames him by suggesting he did not deserve his appointment to the board of State Water Corporation, or that he was only appointed because of the cash donation.

As well as arguing the substantial truth of the allegation, Fairfax Media says the article contained the opinion of Nicholls and Labor water spokesman Steve Whan.

Later on Monday, a number of friends and family gave evidence as to Mr Di Girolamo's character before and after the articles were published.

His younger brother Joseph said on the morning of one of the articles he visited and "I saw a man that was broken".

"He was shattered, he was upset, he was distressed," he said.

Channel 7 Morning Show infomercials presenter Karen Ledbury said Mr Di Girolamo, a long-time friend of her and her husband, appeared "damaged".

Madeline Carter's husband David is a partner at law firm DibbsBarker, which is acting for Mr Di Girolamo in these proceedings. She told the court Mr Di Girolamo's reputation was "smashed" and she had noticed a change in his personality from a gregarious man to someone more withdrawn.

"There was an assumption of guilt given the quantity of the articles about him. It was assumed it was correct by [my] family members, friends, people at school."

The trial before Justice Christine Adamson continues.