TD Paul Murphy was among four men arrested this morning on suspicion of false imprisonment by gardai investigating an incident involving Tanaiste Joan Burton.
Gardai carried out the dawn operation at different addresses across south Dublin.
The arrests were in relation to an incident in Jobstown where Ms Burton was trapped in her car for more than two hours by water charge protesters last November.
Socialist TD Joe Higgins today claimed the arrest of Mr Murphy and two anti-austerity alliance councillors was "a disgraceful and criminal waste of garda time and resources".
The arrested men, aged between 30 and 50, were being held at Terenure, Crumlin, Tallaght and Rathfarnham garda stations for questioning in relation to the controversial protest.
An Anti-Austerity Alliance source said a number of gardai had gone to the homes of Paul Murphy and Tallaght Central South Dublin County Councillor Kieran Mahon at 7am this morning to arrest them.
Another local Tallaght Central Anti-Austerity Alliance councillor, Mick Murphy, was arrested as he left his home to go to work, sources said.
The fourth man arrested was Scott Masterson, a spokesperson for the Tallaght Eirigi Republican group.
Joe Higgins said that the arrests were politically motivated.
He said it was "disgraceful" and "outrageous" that six gardai entered Mr Murphy's home this morning shortly after 7am.
Speaking on the Pat Kenny show on Newstalk today, Paul Murphy's partner Farah Mokhtareizadeh said that they weren't expecting the early morning arrest.
"There were six officers all there who came inside and in a gruff way told him he had to go with them right away," she said.
"He was still in his pyjamas and had to ask them could he change his clothes.
"There were statements from the government about following up on the protests so we had to be prepared, but we certainly didn't expect it.
"Paul has not done anything wrong, so we thought it would be incredibly stupid of the government to come and arrest him."
The men are being questioned in relation to investigations concerning public order offences and false imprisonment on Saturday, November 15 last.
Joan Burton was surrounded by anti-water charge protesters as she left and around 100 protesters blockaded her vehicle as she tried to leave.
Despite a strong garda presence trying to protect the Labour leader and Tanaiste's car, protesters still managed to bang loudly on the roof, bonnet and windscreen shouting "shame on you" and "peaceful protest".
As she was being transferred to a garda car a water balloon was thrown at her, hitting her on the head.
Gardai used pepper spray to try and quell the disturbance, and the garda helicopter, members of the Public Order Unit, as well as reinforcements from surrounding stations rushed to the scene.
Gardai received a number of complaints about the way the protest was conducted and also carried out their own investigations into possible criminality at the protest.
Paul Murphy, a TD for Dublin South-West, and the others, were arrested under Section 4 of the Criminal Justice Act and can be held for up to 24 hours.
Mr Murphy was due to speak at an anti-water charge event in Kilkenny at 8pm this evening.
Not long after the protests of November 15 Paul Murphy said he would "co-operate fully" with gardai if they wanted to talk to him about the event.
Detectives examined footage and photographs from the incident to establish what level of involvement individuals had and what potential charges they could face.
Officers examined whether Paul Murphy could be regarded as having been "in charge" of the protest when he used a megaphone to address the crowd in Jobstown.
Paul has insisted the demonstration was a peaceful one.
"I would be very, very, very surprised if people are arrested following the protest in Jobstown," he said earlier.