The Irish Rugby Football Union will punish clubs who sell their Grand Slam showdown ticket allocations for profit.
Tickets for Sunday's RBS 6 Nations Ireland-England clash at Lansdowne Road are reportedly changing hands for up to €3000.
Thousands of ticketless England fans - as well as 7,000 with tickets -are expected in Dublin this weekend, and the IRFU fears home advantage may be diluted as their stadium is turned into a mini-Twickenham.
IRFU chief executive Philip Browne warned clubs of the consequences if any are found to be selling their allocations at well above the highest face-value price of €57 Euros.
He said: "If the club has been found to have abused their ticket allocation we will take punitive action which could include the club losing their allocation for future matches.
"Every ticket is numbered, so we will know where it has come from.
"If people find they've paid over the odds, above the face value for a ticket, they should send the ticket stub to us at the IRFU - and we'll certainly ensure that we'll follow it up.
"We will be able to track the ticket back to the club.
"We have to look after our own. The problem is that ordinary fans are not getting the chance to see the game."