Gardaí are investigating the vandalism yesterday of the Thomond Park rugby ground in Limerick.
Thomond Park, where Munster plays its home games, had hundreds of holes dug into the surface between 4pm and 6pm yesterday, according to gardaí.
Gardaí are viewing CCTV footage that apparently shows two individuals, their faces obscured by hoodies, digging holes into the pitch.
Thomond Park holds great memories for rugby fans, not just in Ireland, but around the world. In 1978 it staged one of the most famous upsets, when Munster conquered the mighty All Blacks.
The IRFU is planning a redevelopment of Thomond Park that would eventually allow the Limerick ground to double its current capacity of 13,000.
However, the plans would see the demolition of houses on nearby Knocklisheen Road. It is believed the residents of the road have been offered a total of more than €3.5 million by the rugby union to sell their homes and talks for the purchase of the houses are ongoing.
It is understood that the financial package offered to buy 12 privately owned homes and three local authority houses includes €200,000 for each house plus €40,000 in disturbance money.
A spokesman for the Irish Rugby Football Union (IRFU) said it could take up to five days to repair the hundreds of holes, but Munster's home game against Llanelli tomorrow week is not expected to be affected.
Pat Geraghty, Munster branch spokesman, said: "It just seems like one of those unexpected mindless acts of violence. It is a senseless act of vandalism.
"We are not aware of anything that could have happened that would lead me to believe that it was some dispute. There's no reason we can think of, or anybody with any grudges against us, or the branch, or an individual."
Mr Geraghty said: "It beggars belief really as to why someone would do this. Everyone in the Munster branch is mystified and everyone is determined to catch those responsible."
The first indications the vandalism had taken place came after members of the Munster branch of the IRFU arrived at the ground last night for a special reception.