Broncos winger Josiah Karapani has been issued an on-the-spot fine and banned from Brisbane's Fortitude Valley precinct, following an alleged incident overnight.

Queensland police said officers issued an infringement notice for public nuisance, along with a banning notice valid for 28 days, just after 3:30am on Saturday.

The alleged incident took place only hours after Karapani's appearance in the Broncos' 26-12 victory in the Battle of Brisbane clash with the Dolphins on Friday night.

Public nuisance is defined in Queensland law as behaviour that is disorderly, offensive, threatening, or violent, and interferes with public enjoyment of public places.

Police said the infringement was issued in the wake of a disturbance involving a number of people, but it was unclear whether Karapani was involved.

In a statement, the Broncos organisation said the NRL integrity unit had been informed.

"The Brisbane Broncos confirm that Josiah Karapani has received a Queensland Police Service infringement notice for the offence of 'Public Nuisance' and a banning notice after police spoke to him in Ann St, Fortitude Valley around 3.30am this morning," the statement read.

Karapani joined the Broncos in 2024 and made his debut the same year.

He was considered a key player in last season's premiership-winning Broncos run, scoring 11 tries.

He remains under contract with the Broncos at least until the end of the 2027 season.