Gardaí in Limerick were last night examining a note found at the scene of a "mindless act of vandalism" at the city's hallowed rugby ground, Thomond Park.
Hundreds of sods of turf were dug up by vandals at the pitch last Wednesday.
It has since emerged that gardaí investigating the incident found a handwritten note on the pitch while examining the crime scene.
While the contents of the note have not been revealed officially, it is understood the note contained obscene language directed towards gardaí.
The damage is believed to have been carried out by two men wearing hooded jackets who ran the whole length of the pitch, from the Ballynanty end to the Mayorstone end, which is located beside Mayorstone Garda station.
IRFU personnel travelled to Limerick yesterday to assess the damage, which is expected to run into tens of thousands of euro.
The grounds will remain closed for five weeks to repair the damage.
Investigating gardaí are examining CCTV footage taken from the grounds, and last night Chief Supt Willie Keane appealed for information from anyone who may have witnessed the incident.
"This was a mindless act of vandalism that took place in broad daylight between 5.15pm and 6.30pm so there are definitely some witnesses out there, and we would appeal to them to contact the Garda," said Supt Keane.
A number of fixtures due to be played at Thomond Park this weekend, including the junior interprovincial match between Munster and Leinster, have had to be switched to alternative venues. The IRFU said the pitch would be unplayable until October 22nd.