St. George Illawarra's latest signing, Luciano Leilua, is under scrutiny by the NRL for failing to disclose a recent drink-driving incident.

Both the North Queensland Cowboys and the NRL were unaware of the offense for weeks until a local newspaper editor tipped them off, according to The Daily Telegraph.

The Townsville Bulletin's editor, Cas Garvey, reached out to Cowboys CEO Jeff Reibel when Leilua attended court on February 7, under-dressed and without legal representation.

The NRL Integrity Unit was immediately made aware of the situation, nearly three weeks after the initial charge.

According to NRL regulations, clubs and players must report any police charges or off-field incidents immediately. Leilua was stopped by police on January 21 in Townsville, recording a blood-alcohol level slightly above the legal limit.

Despite pleading guilty, being fined and copping a driving suspension, Leilua didn't disclose this to his manager, Mario Tartak, until recently.

St. George Illawarra had initially held reservations before signing Leilua to a three-year contract worth a rumoured $900,000 per season, even after North Queensland Cowboys' club sources reportedly described a lacklustre attitude to training.

Despite concerns, head coach Shane Flanagan believes Leilua will significantly bolster the team's performance, provided his off-field behavior improves.

An NRL spokesperson has confirmed awareness of the matter and ongoing communication with relevant parties.