The former judge who led the Independent Commission Against Corruption during its landmark inquiries into Eddie Obeid and other Labor figures has condemned a plan to restructure the agency as a "bureaucratic monstrosity" that would impede its work.

David Ipp, QC, said a Department of Premier and Cabinet proposal to replace the head of ICAC with a panel of three commissioners would create "an unnecessarily expensive and top-heavy absurdity".

Former ICAC commissioner David Ipp, QC, presiding over landmark inquiries in 2013. Credit:Wolter Peeters

In a blistering submission to a parliamentary inquiry considering the plan, Mr Ipp said the department's recommendations were "merely products of speculation" by bureaucrats lacking any "know-how and understanding" of how ICAC was managed.

It appeared "strikingly disingenuous" to suggest the restructure was consistent with the government's commitment to a strong and effective ICAC, the former Court of Appeal judge said.