The first legislation of the new Irish State was the Coroners (Amendment) Act 1927 where the coroner was deemed to be an office to which the Local Authorities (Officers and Employees) Act 1926 applied, though with the Minister for Justice as the relevant Minister.
Essentially, that provision remains and the current legislation, the Coroners Act, 1962, states in section 9 that - "Every coroner shall be paid by the local authority by whom he is appointed such salary as shall from time to time be fixed, with the approval of the Minister, by that local authority.