Controversy over the preservation of No 16 Moore Street deepened yesterday after Dublin City Council said the building may not have been number 16 at the time of the Easter Rising in Dublin in 1916.
The council confirmed that a renumbering scheme in Moore Street in the 1930s could mean that the last headquarters of the leaders of the Easter Rising may in fact be the building now known as 18 Moore Street.
Yesterday, Minister for the Environment Dick Roche formally asked the council to list the building currently known as 16 Moore Street for preservation.
Martin Kavanagh of the council said architect Gráinne Shaffrey of Shaffrey and Associates, and urban historian John Montague, had been asked to determine if the current number 16 was the house occupied by the rebel leaders, as part of their survey of the building.
Mr Kavanagh said initial research by the council into numbering changes had thrown up the possibility that the building at the centre of the controversy was not the one used by the 1916 leaders.
"There is a danger that this is the case," he said. "There is an indication, from what we have found, that there may have been a change in numbers on the houses on Moore Street." He said Ms Shaffrey and Mr Montague are expected to report in a week or so.
The council also has old photographs showing the facade of houses in Moore Street, including the current numbers 16 and 18, in rubble. It believes the present front of the terraced buildings could date from the late 1920s.
While there is no doubt that the 1916 leaders did take refuge in a house on Moore Street, the main battle took place in the GPO and the actual surrender in Parnell Street. Critics have suggested that the GPO would make a better setting for any proposed commemorative museum.
However, the National Graves Committee rejected the possible confusion yesterday, describing it as "a council ploy".
Spokesman Matt Doyle said the building had been carrying a plaque "for decades" attesting to its being the last headquarters of the 1916 leaders.
A vast number of academics had accepted the building as the last headquarters "of the provisional government", he said.