Shortly after his arrest the Indian government offered to release the 74-year-old campaigner, prompting hundreds of his supporters to gather outside the prison to celebrate.
Pundits suggested that this oldcampaigner, who moved across to Mr Barak from the Likud, may have sensed the imminent implosion of his new political home.
Two years ago, the 44-year-old campaigner set up a group called India Against Corruption aimed at putting pressure on the government to bring about tough anti-corruption laws.