Manly face possible sanction from the NRL over John Hopoate after the controversial rugby league figure coached the Sea Eagles’ SG Ball side last weekend against the wishes of the game’s governing body.

Hopoate was refused registration by the NRL last year after he wasn’t deemed a fit and proper person to be involved with the game, following a litany of off-field trouble.

The 42-year-old’s side was thumped 42-18 by Newcastle on Saturday at Brookvale Oval. But worse might still be to come for the Sea Eagles, with the club facing a possible breach notice over Hopoate’s involvement and a significant fine. That could come as soon as Friday.

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Hopoate has also represented Manly, Wests Tigers and Northern Eagles. Photo: Getty

The matter is understood to be under investigation by the head of the NRL’s integrity unit Nick Weeks.

Hopoate’s involvement with the SG Ball side had been okayed by the NSWRL, the elite under-18s competition’s governing body.

“It is our position that John Hopoate has fulfilled the criteria to be an SG Ball coach,” NSWRL boss Dave Trodden told AAP on Thursday.

Those criteria include earning his relevant coaching certificate and acquiring a Working With Children Check.

The two league bodies have been at loggerheads since November over the issue.

The NRL’s position is that officials of every NRL club have to be registered with the league and, as Hopoate has not been granted registration, he is ineligible to be involved in an official capacity with the Sea Eagles.

“The NRL has been in talks with Manly about the matter for some time and those talks are ongoing,” a NRL spokesman told AAP.

Manly could not be reached for comment.

Hopoate, who represented Manly, Wests Tigers and Northern Eagles, courted controversy throughout a 13-year, 209-game first-grade career, during which he represented Australia, NSW and Tonga.

Hopoate has courted controversy throughout his 13-year career. Photo: Getty

The 41-year-old was finally outed from rugby league after he copped a 17-match ban for a 2005 tackle on Keith Galloway. That came after a 12-match ban in 2001 for poking opposition players up the backside.

Hopoate served a total of 45 weeks on the sidelines – a NRL record.

In 2014, Hopoate’s conduct was the subject of a Junior Manly Rugby League investigation after allegedly abusing the referee of an under-10s fixture.

In an interview with AAP, shortly after he was appointed as new Manly coach last year, Trent Barrett acknowledged Hopoate had made mistakes, but praised him as a good person who had a lot to contribute to the club.

“He has a lot to offer as a coach; not a lot of people probably know the real John Hopoate,” Barrett said.

“He is a very generous person, he is a very honest person and I know he does a terrific job with those kids.

“He is more than welcome at our football club.”

-AAP