The incident happened in the second half of Saturday's match when Cessnock defeated Central Charlestown 32-12.

Ms Young is the sister of former Newcastle Knight Mick Young, who was playing for Central.

"I heard the people on the sideline harassing Julie and I went over to see if she was all right," Mr Young said.

"I heard one bloke say 'we're going to rape you' and after the game she was telling me they were saying 'you're not going to leave this ground alive'. That is just insane.

"Even if it wasn't my sister, no girl should have to cop that at work.

"She was just doing her job, and she didn't even make a mistake.

"There were 200 drunk blokes on the hill and there wasn't even one security guard to be seen.

"Julie has been an official for eight or nine years and she's got thick skin and doesn't take too much to heart, but this was just beyond a joke."

Cessnock secretary David Cleaves said the club would do everything possible to make sure this was a one-off incident.

"We certainly don't condone that sort of behaviour," Mr Cleaves said.

"If someone can help us identify the person responsible we will make sure he never walks into Cessnock Sportsground again. If that is what was said, we would like to apologise to Julie profusely."

Mr Fleming has launched an investigation into the incident.

"This is definitely not acceptable and we will have to have a look at what happened," Mr Fleming said.

"We have asked for a report from both clubs and we will act on those reports.

"Getting the clubs to have their own security guards is something that we will have to look seriously at."

Mr Fleming said the league had tried to avoid appointing Ms Young to Central matches but a recent change in administration had led to the mistake.

Ms Young did not return calls from The Herald yesterday.

The incident occurred when referee Shane Smith stopped play mid-way through the second half because he thought he heard Ms Young say that a Cessnock winger had knocked on.

When Ms Young said that was not the case, the rules obliged Mr Smith to pack a scrum with a Central feed because they had the territorial advantage.

Cessnock skipper Ryan Gregory was sent to the sin-bin for comments he made to Mr Smith over the incident, and the Cessnock supporters started shouting at the officials.