"The club has been informed that he attended the opening of a barber shop yesterday, in breach of the protocols.
"He has been placed on a 'COVID Hold' and will undergo testing, while spending 14 days in self-isolation as the NRL continues to examine details of the breach.
"The Broncos are investigating the circumstances around the matter to determine what further action may be taken."
It's another shocking blow for the Broncos who are enduring the season from hell. They sit second-last on the ladder and have lost 10 of 11 games since the campaign restarted in late May after a coronavirus-enforced hiatus.
Yesterday the club announced coach Anthony Seibold will spend 14 days self-isolating after he stayed in Sydney on Friday night to deal with a "serious family matter".
It's a cruel setback in a professional sense for Seibold, who is under enormous pressure to keep his job despite being in the second year of a five-year deal.
Three members of the Broncos' coaching staff — including club legend Allan Langer — were also penalised for biosecurity breaches before the Rabbitohs game after meeting at a pub to celebrate Langer's birthday.