A former Sinn Féin party member was arrested in connection with the attack on Michelle Mulherin's office, according to the Irish Independent.
A fire broke out at Michelle Mulherin's office in Ballina, Co Mayo at around 7 o'clock on Tuesday evening.
Gardaí had been called to investigate damage to a window, when they spotted the blaze.
There was nobody in the office at the time. A unit from the Mayo County Fire Service attended the scene and the fire was quickly put out.
Ms Mulherin released a brief statement following the incident.
"Gardaí are investigating an incident at my office in Ballina, Co. Mayo, this evening. Thankfully nobody was injured.
"I await the outcome of the Garda investigation and will be making no further comment at this stage," she said.
A man was questioned and later released by police without charge. The paper reports that he was an active member of Sinn Féin in the 1990s but left more than a decade ago.
