The National Rugby League blamed a "technical error in the Ticketek system" for allowing online ticket sales to non-members of two clubs today.
Ticket sales today were meant to have been limited to only the clubs' members.
"The NRL apologises for any inconvenience caused to our club members as a result of this system failure beyond our control," chief operating officer Graham Annesley said.
Ticket sales were suspended while the glitch was ironed out. They had resumed by lunch time.