Paris (AFP) - Champions Cup organisers European Professional Club Rugby (EPCR) said on Tuesday it has started an investigation after last weekend's game between Ulster and La Rochelle was moved to Lansdowne Road.
The group fixture was originally set to be played in Belfast's Ravenhill Stadium but was changed 160 kilometres (100 miles) south to Dublin, in front of an empty ground, because of heavy snow in Northern Ireland.
The 1999 champions had been using a protective cover and heaters to thaw out the Ravenhill pitch.
"EPCR can confirm that an investigation is being conducted to ascertain the facts surrounding the relocation of last Saturday's Heineken Champions Cup, Round 2 fixture between Ulster Rugby and Stade Rochelais," EPCR said.
"The investigation is proceeding under the terms of the 2022/23 EPCR Disciplinary Rules, and Ulster Rugby have been requested to co-operate fully.
"Please note that EPCR will be making no further comment until this process has been concluded," it added.
Ulster chief executive Jonny Petrie said the decision to switch the match was "frustrating".
During the game it emerged that travelling La Rochelle supporters had managed to make their way into the Belfast stadium to watch the fixture.
The French side, the Champions Cup holders, won 36-29 and Ulster's next home game will be in the United Rugby Championship on January 1.
