The Irish Nurses and Midwives Organisation (INMO) has asked Paddy Cosgrave to apologise for tweeting a "scaremongering" claim that four nurses had died due to Covid-19.
INMO general secretary Phil Ni Sheaghdha said the Web Summit founder was spreading misinformation and may have alarmed the families of nurses with his incorrect tweet.
On Monday night, Mr Cosgrave tweeted to the "4 nurses who fought so hard for so many patients, but who themselves fell ill, and have now passed. RIP." On Tuesday, the HSE was forced to take the unprecedented step of publishing its own tweet to counter the incorrect claim.
"Contrary to tweets sent yesterday - thankfully none of our nurses have died from Covid-19," it said.
The tweet has remained on Mr Cosgrave's account, which has over 55,000 followers. Ms Ni Sheaghdha told the Irish Independent that she believes Mr Cosgrave should apologise for his "incorrect" claim.
"Families may very well be sitting at home and reading something like that, and knowing that a healthcare worker they know is sick," she said.
A spokeswoman for the Web Summit referred questions from the Irish Independent to Mr Cosgrave. Mr Cosgrave did not respond.