A prominent Sydney barrister has been reprimanded for unsatisfactory professional conduct during a Supreme Court case in which he acted for the family of the now jailed former state minister Eddie Obeid.

The NSW Bar Council has determined that not only should Robert Newlinds, SC, be reprimanded but he must apologise in writing to David Ipp, QC, a former Supreme Court judge and the former commissioner of the Independent Commission Against Corruption.

Barrister Robert Newlinds, SC, at the NSW Supreme Court in a file picture. Credit:Peter Braig

Mr Newlinds represented the former Labor powerbroker and three of his sons - Paul, Moses and Eddie Obeid jnr - in an unsuccessful legal battle that the family brought against the corruption watchdog, the State of NSW, Mr Ipp, counsel assisting Geoffrey Watson, SC, and several ICAC investigators.

Justice David Hammerschlag later blasted the Obeids for their "unreasonable" and "irresponsible" lawsuit against the corruption watchdog and ordered the family to pay the multimillion-dollar legal bills of the ICAC parties, which they are yet to do.