Young people have been warned against taking part in "Neknominate", a drinking craze which has swept the nation, following the deaths of two men who had participated in the game.
Ross Cummins, 22, and Jonny Byrne, 19, both died after being nominated by friends to take up the Neknominate challenge - which involves filming yourself drinking large amounts of alcohol and posting the footage on Facebook.
The deaths of the two young men, both Northern Irish nationals, have prompted the NI Neknominate Facebook page to be closed down.
Cummins was found unconscious in his Dublin home on Saturday morning and died later in hospital amid reports he was drinking spirits shortly before his death.
Byrne died after he plunged into a river near his house after completing the online challenge and downing alcohol.
Cummins (left) and Byrne are believed to have died following playing Neknominate
Writing on Facebook, his brother Patrick urged others to stop playing the deadly game: "My young 19-year-old brother, Jonny Byrne from Carlow, died tonight in the middle of his nomination.
"He thought he had to try and beat the competition after he necked his pint he jumped into the river.
"If people have any decency and respect they will refrain from any more this."
Patrick added: "I jumped in to try and save him and I had him nearly out, but he broke free from me and pushed me under the water, and I was nearly gone, only for my girlfriend and a passerby jumped in and pulled me out," he said.
"People are now just doing stupid acts to try to better each other.
"A guy who turned down a challenge last week was called a chicken and a coward for turning it down. Basically what it has turned into now is a bullying competition.”
The Irish Republic’s communications minister Pat Rabbitte urged Facebook to take action, saying: "It would be helpful if Facebook agreed to take down pages, which promote a stupid and silly phenomenon."
A spokesperson for Facebook said: "We do not tolerate content which is directly harmful, for example bullying, but controversial or offensive behaviour is not necessarily against our rules."
Alcohol Action Ireland said: "While some may see this as a game, the consequences of drinking large volumes of alcohol in a short period of time can have very real consequences for those taking part.
"We would call on people to look after their health and wellbeing by not participating in this 'game' and to also protect their friends from the serious risks associated with it by not nominating them to take part in it."