Players had to change next to bins in squalid conditions ahead of their inter-pro derby at Energia Park.
The IRFU has asked for reports from Connacht and Leinster regarding last week's facilities at Energia Park.
The association has agreed to a Connacht request to investigate why they and Ulster were forced to change in temporary facilities close to bins.
The IRFU say they are appalled by the situation.
Controversy erupted following a widespread online video showing the filthy changing facilities that were set up for the women's inter-pro finale, with rats reportedly scurrying nearby.https://t.co/IsDDF6lvR9
— Irish Independent Sport (@IndoSport) September 16, 2021