The teenager who allegedly threw a brick at a garda van during anti-water protests had nothing to say after his release from garda custody.
Dylan Collins (19) was arrested yesterday by gardai investigating the protest in Jobstown, where Tanaiste Joan Burton was trapped in her car for more than two hours.
Mr Collins refused to comment when approached outside his home minutes after he had been released from Tallaght Garda Station.
"I'm not giving any statement," he said.
The Herald can also reveal that Tanaiste Joan Burton will be the key witness in court prosecutions that the DPP could bring against a number of water protesters.
The revelation came after four people who were arrested yesterday morning about their alleged activities were all released without charge.
Ms Burton made a detailed statement to gardai just five days after the protest on the afternoon of November 15 last.
She met with gardai for more than an hour on November 20 and "gave her version of events as they unfolded" according to her spokesman at the time.
Sources said that if Anti-Austerity Alliance TD Paul Murphy, who was arrested and released on Monday, is charged with Ms Burton's false imprisonment, then her evidence would be "absolutely vital in a court of law".
"Her evidence would also be required in relation to a number of other protesters," the source added.
Ms Burton was held in her vehicle and was also hit with a water balloon. She previously said missiles were thrown and homophobic and anti-women abuse was hurled at gardai.
Speaking afterwards she made a detailed statement to gardai, Ms Burton said she got a "bad bang" on the back of her neck during the incident.
She pointed out that 100 demonstrators surrounded her car, banging on the roof and windows.
Ms Burton added: "The one thing I'm really upset by about the protesters is their language."
Meanwhile, a 14-year-old boy who was arrested at his Tallaght home on suspicion of public order offences was also released without charge yesterday.
More arrests are expected in the coming days as gardai finalise their investigation into the protest.
A total of eleven people have now been arrested so far.