The Irish Aviation Authority has launched an investigation into the use of a drone near the site of a crash in Co Tipperary as first responders attended the scene.
The semi-state air space regulator said it infringed regulations aimed at protecting emergency response efforts.
Three 18-year-old Leaving Cert students – Zoey Coffey, Nicole Murphy and Grace McSweeney – and Ms McSweeney’s 24-year-old brother Luke died in Clonmel after the car they were travelling in overturned and hit a wall on Friday night.
The tragedy has drawn the sympathies of the nation, with a vigil on Sunday night drawing around 2,000 people who gathered to mourn the loss of four young locals.
After their names were confirmed on Saturday, Garda Superintendent Kieran Ruane said the use of the drone had been “disrespectful” to the grieving families and first responders.
Father Michael Toomey, a chaplain at a Clonmel school, said there had been anger at the use of a drone at the scene of the crash.
In a statement on Monday, the aviation authority expressed its “deepest sympathies” to the families and friends of those killed and said an investigation had been launched.
“The actions of the drone operator at Mountain Road, Clonmel, Co Tipperary, were an invasion of privacy and posed a flight safety risk,” it said.
“This activity is also in direct contravention of the drone regulations.
“Remote pilots and drone operators are required, by European regulation, to avoid areas where an emergency response effort is ongoing.
“This is safety-critical as it could hinder possible aerial support and to protect the privacy rights of persons involved in the emergency event.
“An IAA investigation has commenced and we are in contact with An Garda Siochana on the matter.”