The Tánaiste's leaking of a GP contract to a rival union was discussed in a speech at the opening of Web Summit on Monday night.
The Irish co-founder of Web Summit, Paddy Cosgrave, made the comments about Leo Varadkar's leaking of the deal with the Irish Medical Organisation (IMO) to the National Association of General Practitioners, then led by Mr Varadkar's friend Dr Maitiú Ó Tuathail, as part of his introduction of the event's keynote speaker, Facebook whistleblower Frances Haugen.
Mr Cosgrave said the organisation Whistleblower Aid had assisted in the breaking of the story in Village Magazine last year, the Irish Examiner reports.
He described the reporting from Chay Bowes as a "devastating exposé".
Mr Cosgrave brought Mr Bowes, Village Magazine's Michael Smith, and Whistleblower Aid's John Tye on to the stage before encouraging the audience to give them a round of applause.
The National Bureau of Criminal Investigation (NBCI) is currently investigating the matter after a complaint was made last November.
Mr Varadkar has admitted sharing a copy of a new pay agreement between the Department of Health and the IMO with Dr Ó Tuathail.
He has has denied any wrongdoing in relation to the incident.
Web Summit was founded in Dublin in 2009 and Mr Cosgrave moved the event to Lisbon in 2016. This week's event is expected to attract more than 40,000 people.
Former British deputy prime minister Nick Clegg, now vice president of Facebook, are among the main speakers.
Former footballers Thierry Henry and Samuel E’to are also due to speak at event.