A health bureaucrat has skimmed more than $500,000 in undeserved overtime payments from a fund meant to cover the costs of cancer research trials, according to a Corruption and Crime Commission report tabled in Parliament this morning.

Long-time clinical trials manager at Sir Charles Gairdner Hospital, Judith Innes-Rowe, used a loophole in the Health Department's 30-year-old human resources system to approve overtime she was not entitled to claim.

A clinical trials manager at Sir Charles Gairdner Hospital is under fire after a CCC report was dropped in Parliament on Thursday morning. Credit:Lauren Pilat

Over a five-year period from 2012 to 2017, Ms Innes-Rowe was paid a total of $1.2 million, with her base salary comprising about $600,000 over that period.

Health Minister Roger Cook said Thursday afternoon he was appalled by the "serious misconduct and fraudulent behaviour exposed in the CCC report".