Leinster have confirmed that two players from the senior squad have been tested positive for Covid-19.
The Irish regional side earlier revealed that none of the players or staff reported positive but had postponed their Pro14 derby game against Munster as they were "investigating the outcomes of some of the results".
A statement released from the club confirmed that the positive tested players along with their close contacts are on a self-isolation.
"A number of close contacts of the two players have been identified and are also self-isolating," added Leinster.
"One player was tested outside the PCR testing window, after feeling unwell, and is now self-isolating.
"Further PCR testing was carried out at Leinster Rugby yesterday (Monday) morning on 104 players and staff and 103 tests returned negative results with one senior player testing positive and he is also self-isolating.
"The HSE has been informed in accordance with public health guidelines. The Leinster Rugby squad return to training later on today (Tuesday)."