Police had registered a case under IPC sections 124 (sedition) and 153A (promoting enmity between different groups on grounds of religion, place of birth, residence, language) against Vaiko for a speech he had given while releasing his book, 'Naan Kutram Sattugiren' (I am Making the Accusation), in 2009.
The charge-sheet in the case was filed in 2010. However, the trial is yet to commence. On April 3 this year, Mr Vaiko had appeared before Metropolitan Magistrate S Gopinathan and filed a surrender petition.
Although the magistrate had offered to release Mr Vaiko on bail, he refused to apply for it.
Vaiko was remanded in judicial custody. Later, the MDMK leader was sent to a Central Prison in Chennai's Puzhal area.
Mr Vaiko had moved a bail application yesterday. When it came up for hearing today, Additional City Civil Court Judge Purushothaman granted unconditional bail to him.