Indian politics sunk to a new low Monday when the capital’s chief minister, Arvind Kejriwal, called Prime Minister Narendra Modi a “psychopath.”

India’s federal investigators raided Kejriwal’s office Monday as part of a probe into corruption allegations by a senior bureaucrat in his office.

Kejriwal, who spearheaded India’s anti-corruption movement in 2011, was elected Delhi’s chief minister earlier this year. Kejriwal handpicked the controversial bureaucrat Rajendra Kumar as his top aide. In June, a complaint was filed against Kumar allegding that he set up private companies to bag government contracts more than a decade ago.

Kejriwal tweeted that his office was sealed Monday and that investigators were going through his files. Then he accused Modi of a political vendetta against him.

Since Kejriwal’s stunning victory earlier this year when his Common Man Party nearly wiped out Modi’s Bharatiya Janata Party in the elections, ties have been rough. Kejriwal has repeatedly accused Modi’s government of not letting him function freely.

An official at the Central Bureau of Investigation said the target of the raid was Kumar, not Kejriwal. He said investigators raided a total of 14 locations in New Delhi and in the northern state of Uttar Pradesh. On Twitter, the raid set off a storm.