FORMER Labor minister Eddie Obeid and his sons - Moses, Paul and Eddie Jnr - are suing over their dealings with the New South Wales Independent Commission Against Corruption.
Mr Obeid, who has pleaded not guilty to corruption charges arising out of the ICAC investigations, has issued proceedings against former corruption watchdog chief David Ipp, Sydney lawyer Geoffrey Watson and seven ICAC officers.
The Obeids have accused Mr Watson of behaving in an aggressive, threatening and intimidating manner and say his interviews with the press reveal "antipathy" towards Mr Obeid Snr.
The action seeks a declaration that four reports involving members of the family, and investigations into Obeid-linked company Australian Water Holdings and Liberal Party donations, do not fall within the commission's powers.
The men also want an order to prevent the ICAC from issuing reports on its most recent investigations of the family.
The men say they have suffered damage to their reputations, "irrecoverable legal expenses", stress and mental anxiety.
Mr Watson told the ABC the allegations were contemptible and a disgraceful attack on honest investigators.
"I'm worried about those decent, hard-working and really honest people, the ICAC officers who've been dragged into this," he said.