Australian police have apologised to the family of Irish murder victim Jill Meagher after a photo of her lying in a shallow grave was shown to an audience by a police detective who had investigated her killing.

The Australian newspaper the Herald Sun says the image was shown to a group of around 400 men at a cancer fundraising event in the state of Victoria last week.

Detective Senior Sergeant Ron Iddles displayed the photo while giving a talk to the event about his years as a homicide detective.

Victoria Police have offered the family of Jill Meagher its sincerest apologies for what its called an "unfortunate error".

Acting Deputy Commissioner Steve Fontana last night apologised for Mr. Iddles and banned all public presentations on operational matters by officers until new rules were put in place.

He told the paper "This was a deeply unfortunate error of judgment and my sincere apologies are extended to Jill's family, friends, the community, and in particular to her husband, Tom".

Members of the audience have said they were upset by the graphic photograph.

The Louth journalist was raped and murdered by Adrian Ernest-Bayley as she walked home from a night out in Melbourne last year.

Bayley was jailed for 35 years and has failed in an appeal to have the sentence reduced on the grounds that it was unduly harsh.