A public campaign attacking Joe Karam's reputation led to the "worst four years" of his life, a court has been told.
The longtime David Bain supporter's defamation case against two Justice for Robin Bain members opened in the High Court at Auckland today.
Mr Karam's lawyer Michael Reed, QC, said in his opening address that Kent Parker and Victor Purkiss had "laid siege" to his client's reputation with comments on Facebook and the internet.
Mr Parker is acting for himself in the case before Justice Patricia Courtney. His co-alleged was not in court yesterday and Mr Parker said he had not heard from him for some time.
Mr Reed told the court comments by the pair had essentially attacked Mr Karam's motivation for supporting David Bain.
They began after Mr Bain's 2009 not guilty verdict, he said.
Mr Parker and Mr Purkiss suggested Mr Karam had "knowingly and deliberately perverted the court of justice through a cunning scheme of propaganda'', Mr Reed said.
The comments made alleged Mr Karam's support of Mr Bain had been "purely cynical" and that he "aided and abetted a murderer".
They had caused distress, anxiety and hurt to his client, Mr Reed said.
Mr Karam also gave evidence today, describing how he became involved in Mr Bain's case.
His son Richard was among a number of supporters in the public gallery.
The trial continues.