The cap worn by Michael Collins on the day he was gunned down at Beal na mBlath was removed from public display because blood and brain residue were visible on it.
For decades, the cap and greatcoat worn by Collins that day were displayed at the museum in Kildare St.
However, when the Collins exhibition was moved to Collins Barracks in 2006, a review was carried out in the light of “modern” museum ethics.
Audrey Whitty of the National Museum said: “The cap is no longer on display and one of the reasons is due to the sensitivity of General Collins’s blood and organic matter on the object, which is an integral part of the artefact itself.”
Dr Whitty said Collins’s cap and coat did not both have to be on display to tell the story of Beal na mBlath.
“The blood on the greatcoat is more subtle and not as graphic and it has the mud from the scene that day at Beal na mBlath,” she said.
She added that the cap is preserved and can be viewed by prior appointment.
The decision to remove the cap from public view was taken by curators, who considered the sensitivities of the descendants of Michael Collins. It was also in line with “modern” museum ethics.
Dr Whitty said there is still a fascination with anything belonging to Collins.
“Curators, in taking the decision on the cap, realised the coat, with the mud stains and blood, would have told the story on its own, regardless,” she said.
She said when it comes to the curatorial, less is more.
“If you crowd a cabinet full of, say, 10 objects and you have a star item, it loses its importance,” she said.
“That particular object is surrounded by another nine.”