The NRL has issued a warning letter to Canberra's Jordan Rapana after the winger made an abusive gesture in the direction of the referees during his side's golden point loss to the Cowboys on Saturday night.

Rapana raised both of his middle fingers towards the match officials after he was denied what would have been the match-winning try in extra-time against North Queensland.

The NRL has responded by issuing the New Zealand international with a concerning act notice for his actions in an emotion-charged loss to the 2015 premiers, who sealed the win with a miracle try to Gavin Cooper after he chased down a field goal attempt from Johnathan Thurston that ricocheted off the underside of the crossbar.

It is understood Rapana wasn't charged because there was quite some distance between him and the officials, making it impossible to deem his gesture was deliberately meant for the match officials.