Ivan Cleary claims he's never sworn at a match official during his three-decade involvement with professional rugby league and he isn't about to start.

The Penrith coach emphatically dismissed as "completely false" the allegations he launched a verbal tirade at referees Ashley Klein and Dave Munro in the Panthers Stadium tunnel at half-time last Sunday.

Both Klein and Munro were unaware of remarks Cleary allegedly made and the 48-year-old was cleared of wrongdoing by an NRL investigation on Wednesday.

"I certainly didn’t swear. I never have sworn. In 28 years and 500-odd games [of playing and coaching] I've never sworn or abused anybody," Cleary said on Thursday.

"It is laughable on one hand but it's quite upsetting, too, because it's slander really. It's completely untrue.

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"I suppose any kind of mud can sometimes stick. All I can say is I think the NRL have done what was always going to happen because it was just completely false accusations."

Cleary clarified his post-match admission that he "possibly" talked towards Klein and Munro, insisting he only addressed his captain James Tamou, who was in conversation with Klein.

"I was asked whether I spoke to the referees and I said, 'I think so'... The reason I said that was in case one of them thought I did. I certainly didn't speak to Ashley Klein," Cleary said.

It is laughable on one hand but it's quite upsetting, too, because it's slander really... I suppose any kind of mud can sometimes stick Ivan Cleary

Cleary is adamant he did nothing wrong but has assured NRL head of football Graham Annesley he won't enter the tunnel at half-time again.

"I said to Graham that in future I won’t get in the tunnel, but at the end of the day that's all I did," Cleary said.

"I totally respect officials and the need to respect them. I always have done that and I always stand by that."

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Penrith five-eighth James Maloney supported Cleary in saying the mentor hardly uses expletives - even with his players in heated moments.

"He's pretty measured in what he says. So it's a bit weird when he tries to spray you because he sprays you nicely … [Swear words aren't] something he usually throws around," Maloney said.

Maloney had a running battle with Klein during the first half of the Canberra game but maintains he's on good terms with the officials.

"There was a bit of hoo-haa made about it. They made some calls and I got a little bit frustrated and didn't think there was some consistency in a couple of them … In general, I've got no issue," Maloney said.

Maloney, who will depart the Panthers for Catalans Dragons at the end of the season, believes players are confused by a couple of rule interpretations.

"The escort rule at the moment is really strange because there's escorts every game, every week, all over the park," he said.

"Then they pick and choose when to penalise them. And not even penalise, people are going to the sin bin for them.

"I feel like there's a few teething problems with the late hits on ball-players as well. I feel like they’re a bit trigger happy on that. As soon as someone lets the ball go and ends up on the deck, it's 'Penalty, here we go - he's been taken out'.

"It's not the refs. They're just adjudicating on what they're told. But I think a bit of clarity needs to come around areas like that."

Another hot topic at the Panthers is the future of prop Reagan Campbell-Gillard, who has been linked with a move to Parramatta despite having five years to run on his deal.

"Reagan's on contract, he's part of our team," Cleary said.