Amid the ongoing tussle between the Central Bureau of Investigation (CBI) and state governments over the CBI's jurisdiction, Union Minister Jitendra Singh on Thursday said states cannot deny entry to the CBI to probe cases referred by the courts.

The CBI faced a tough situation in West Bengal after its sleuths were detained when they went to question Kolkata police commissioner Rajeev Kumar, with West Bengal Chief Minister Mamata Banerjee taking to the streets and holding a fast in protest.

Recently, the states of Andhra Pradesh, West Bengal and Chhattisgarh have revoked general consent to the CBI to probe any case in the states without the government's permission.

The CBI, which functions under the provisions of the Delhi Special Police Establishment (DSPE) Act, 1946, can probe offences in a state with prior approval of the state government concerned, Singh said.

Constitutional courts can also entrust any case or class of case for investigation in exercise of inherent jurisdiction even without the consent of the respective state government, the minister said in a written reply to Rajya Sabha.

Once general or specific consent is granted under Section 6 of the DSPE Act, by the state government where the case is registered; or when the case is entrusted by the constitutional courts, the powers and jurisdiction of members of the DSPE (CBI) may extend for investigation, he said.

"Withdrawal of consent, if any, by a state government can be effected prospectively and not retrospectively," said Singh.

Furthermore, in the cases which are referred by the Constitutional courts, the entry of CBI investigators cannot be denied by that state as these do not require the consent of the state.

CBI sources have said that Kolkata police commissioner Rajeev Kumar will be questioned on February 9.