Intervening to douse a political fire, the Supreme Court of India on Tuesday issued directions to authorities in a corruption probe on the conduct of the police commissioner of Kolkata, the capital of West Bengal state.

Detectives belonging to India’s federal investigation agency, the Central Bureau of Investigation (CBI), arrived at the home of the commissioner of police, Rajeev Kumar, on Sunday evening in connection with an investigation into a Ponzi scheme. The scandal has seen politicians, businessmen, journalists and film producers implicated. The federal detectives were, however, stopped by state police as Kumar refused to meet them. State police troopers then detained the federal detectives and took them to a police station. They were freed subsequently and returned without being able to question the police commissioner.

Mamata Banerjee, the chief minister of West Bengal, led a sit-in protest on Monday in support of the police commissioner and against what she said is the “political vendetta” of the Narendra Modi-led federal government. Banerjee, who leads a regional party trying to forge a front against Modi’s ruling party, accused the federal government of trying to undermine state powers.

The Supreme Court directed Kumar and the CBI to meet at a “neutral place” in Tuesday’s order and chose Shillong, the capital of Meghalaya state, for this purpose. The three-judge bench, led by Chief Justice Ranjan Gogoi, also issued a notice to the West Bengal government on the CBI’s plea that its officers were “held hostage” by state police. The court restrained the federal agency from taking “coercive action,” including arrest, against Kumar and asked the state’s chief bureaucrat, police chief, and Kumar himself to file their respective replies to the CBI’s contentions by February 18.