A former senior policeman who made racist and abusive comments online will not face charges, despite the anti-corruption agency recognising his behaviour risked damaging the integrity and confidence of police operations.

An 18-month investigation into the conduct of the former assistant commissioner Brett Guerin, who resigned last year after being outed by The Age as the author of a series of online posts about “jigaboos”, “dagoes” and sexual abuse, has found his conduct was "generally offensive" but his activities and views did not affect the outcome of the unit’s inquiries into complaints of police misconduct.

Former Victoria Police superintendent Brett Guerin leaves the Supreme Court in August. Credit:Chris Hopkins

“IBAC’s investigation found no evidence of actual bias. Regardless of this, this behaviour risked damaging the integrity of, and confidence in, Victoria Police investigations,” an IBAC spokeswoman said.

“No charges will be laid against Mr Guerin as while his conduct was generally offensive, it does not meet the standard of ‘offensive’ currently required to file charges under the Criminal Code.”