The head of the Corruption and Crime Commission has used a public lecture in Perth to try to dispel what he says are a number of myths about the watchdog.

The CCC Commissioner, Len Roberts-Smith told the audience at Murdoch University that the Commission's role is to improve the integrity of the public sector, not to conduct criminal investigations.

He noted the CCC was well known in Western Australia but was not well understood.

Mr Roberts-Smith says the despite the public perception, the Triple C does have a good conviction record.

"Of the number who've been charged and cases concluded, the 53, we've got 44 convictions, that's a conviction rate of 83 per cent," he said.

The CCC recently had a win, with the conviction of former Labor Minister Norm Marlborough for giving false testimony.