Disgraced former Labor minister Eddie Obeid is suing former corruption watchdog head David Ipp, Sydney silk Geoffrey Watson, who assisted historic inquiries into the Obeid family, and the state of NSW over a series of explosive investigations into his dealings in state Parliament.

In a statement of claim filed in the Supreme Court on Thursday, lawyers for Mr Obeid and his sons Moses, Paul and Eddie junior seek damages and a declaration that Mr Ipp, Mr Watson, SC, and another seven officers of the Independent Commission Against Corruption "engaged in misfeasance in public office".

Eddie Obeid's lawyers may call Margaret Cunneen in his civil suit against the ICAC. Credit:Nick Moir

It is the latest front in an escalating legal war between the ICAC and high-profile targets of its investigations.

"These allegations are the greatest bunch of rubbish that I have ever read," said Mr Watson, who was senior counsel assisting the commission in a string of inquiries involving Mr Obeid senior and his sons.