Sharks back rower Reni Maitua has let himself and the game of rugby league down by testing positive to a banned substance, NSW Premier Nathan Rees says.

Maitua has been stood down by the NRL after failing a drugs test, but has exercised his right to have his second sample tested which will return a result in seven days.

The revelation came just weeks after a 2002 group sex scandal rocked the Cronulla club after the ABC Four Corners program aired details of the incident.

Mr Rees said Maitua was another "bad apple" who had tarnished the game of rugby league.

"It's a good game - the administrators are good, but again another bad apple, or what appears to be a bad apple," Mr Rees told reporters in Sydney.

"We just had the heritage round, which should have been the focus of attention for rugby league in recent weeks and it wasn't, for all the wrong reasons.

"People aren't just letting themselves down, they're letting their code down. They engaged in conduct and behaviour that is not becoming of the game."

Brought to you by AAP © 2024 AAP