The Union Ministry of Home Affairs told the Bengal government Tuesday that Kumar had sat in on the dharna with West Bengal Chief Minister Mamata Banerjee — and that that was in contravention of the All India Services (Conduct) rules, 1968 and All India Services (Discipline and Appeal) Rules, 1969.
The home ministry is the controlling authority of Indian Police Service officers.
The current political crisis between the Bengal government and the Centre was triggered after a CBI team showed up Sunday at Kumar's home. The CBI accused the Kolkata Police chief of slow-walking the investigations into the alleged Saradha and Rose Valley ponzi schemes.
Five members of the CBI team were detained on Sunday, but later released.
Mamata had announced her dharna — saying it was to "Save the Constitution" — after Sunday's fracas. She had said the CBI showing up unannounced at the Kolkata Police chief's home was a "destruction of the federal structure".
The CBI has taken Kumar to the Supreme Court, accusing him of destroying evidence in the investigations. On Tuesday, the court ordered Kumar to join the CBI investigation. It also ordered that he could not be arrested.
On Monday, when the CBI made the charge that Kumar was destroying evidence, the court said there was nothing in its submission to prove the claim. It added however that it would come down very heavily on Kumar should the CBI put forward any evidence to prove its claim.
It was the Supreme Court that had handed the investigations into the alleged Saradha and Rose Valley ponzi schemes to the CBI. The SIT (special investigation team) team investigating the alleged scams was being headed by Kumar.