Gardai said a man in his late 20s and a woman in her early 50s were detained over the death of James Cahillane in Co Kerry over a year ago.
Mr Cahillane was found dead after a fire destroyed his home at Ardraw, Beaufort, near Killorglin, on April 19 last year.
The man and woman were being questioned separately under section four of the Criminal Justice Act 1984 and section 30 of the Offences of the State Act 1939 respectively.
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