However, Ramadoss could not walk out of the prison at Tiruchirappally in view of other pending cases.
The PMK founder was arrested on April 30 for trying to stage a protest demanding arrest of "true culprits" behind the violence at Marakkanam in Villupuram district, allegedly targeted against Dalits.
Chief Minister J Jayalalithaa had blamed the party for the violence.
He was arrested under different sections including Unlawful Assembly, Activities prejudicial to Peace, Violation of Police Rules,and the offence of acting against General Public - under the Amended criminal Law.
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Protests were held near Kanchipuram opposing Anbumani's arrest, which comes two days after police action against his father.
In the wake of the developments, some preventive arrests were made including in northern districts which has a sizeable population of Vanniyars, the community PMK claims to represent, police said.
Violence had erupted following the arrest of Ramadoss on April 30, with many government buses being torched by miscreants.