CBI joint director Pankaj Srivastava said the agency's officials had gone to Kolkata Police commissioner Rajeev Kumar's residence to question him in chit fund scan cases on Sunday and "we would have rounded him up if he hadn't cooperated with us". The CBI move took an unprecedented turn after the team was stopped from entering the house and a number of agency officers were bundled into police jeeps, whisked to a police station and detained. Soon after West Bengal Chief Minister landed at Kumar's residence and fired salvo at the Centre, alleging political vindictiveness. In a tit-for-tat move, a team of Kolkata Police officials reached the CGO Complex - the state headquarters of CBI. Reacting to the fast-paced developments, Srivastava said, "We had gone there to investigate him. And if he hadn't cooperated with us we would have rounded him up." Asked about police officials cordoning off the CBI offices and his residence, he said, "I have also been detained and there are police officers standing outside my house." However, Joint Commissioner of Police (Crime) Pravin Tripathi said the CBI officers have been let go from the police station after questioning. "They just said they had come for a secret operation. We don't know what kind of operation it is," Tripathi said. Later in the evening, central forces arrived at the CBI office in Kolkata which was already cordoned off by the city police, officials said.