The GAA have cancelled a number of tickets for Dublin's upcoming All-Ireland Senior Football Championship clash with Tyrone.
Some tickets for the hotly anticipated semi-final were being offered for sale on non-official platforms, including the Ticketmaster-owned website - Seatwave, for up to four times their face value.
The GAA released a statement yesterday to say they have contacted the outlets in question.
"Requests have also been made directly to platforms selling tickets above face value to remove them from sale and the situation continues to be monitored by the GAA’s ticket office."
People wishing to attend the last-four match-up at Croke Park on August are also advised against buying tickets from non-official outlets.
"Supporters and members are urged not to buy tickets from unofficial sources for above face value as they risk purchasing tickets that may be cancelled."
Meanwhile stand tickets for Sunday's second GAA Hurling semi-final involving Cork and Waterford (senior) and Cork and Dublin (minor) at Croke Park are expected to sell out.
Remaining stand and terrace tickets can be purchased from the usual ticket outlets including gaa.ie/tickets as well as selected SuperValu and Centra stores nationwide.