In Delegat's case, policewoman Alana Kane received a black eye and facial injuries after Delegat continued to punch her despite her going unconscious.

However, there was no prison sentence for him - instead he got community service and a fine.

AUT law professor Warren Brookbanks told Story there is often a difference in the sentences handed out for crimes based on ethnic background, but that's mainly because details of each case vary.

"Sometimes there are examples of unconscious bias on the part of the judiciary - but I think more often it simply reflects the fact that the facts in any case are invariably very, very different," he said.

However Mr Brookbanks admits it doesn't seem to add up in this case.

"There's a huge difference between a penalty of 300 hours' community service and nine months' imprisonment, for what seem to be very similar facts," he said.

Newshub.