New Delhi, Jul 12 (IANS): The CBI on Wednesday conducted raids at 23 locations in West Bengal and Jharkhand in connection with a graft case registered against the Principal Commissioner of Income Tax and others, an official said.

The Central Bureau of Investigation (CBI) took the step against Principal Commissioner Tapas Kumar Dutta, posted in Ranchi, and three of his colleagues following allegations of criminal conspiracy.

They were accused of favouring private persons and companies in the matter of taxes and for taking illegal gratification.

The CBI raids took place at 18 residential and office premises of the accused in Kolkata and five places in Ranchi in Jharkhand, a CBI official said.

"It is alleged that Dutta and three other Income Tax officials conspired with six private persons, including a chartered accountant, and some unidentified persons," the official added.

The CBI officers questioned Dutta at the IT office in Ranchi. Sources in the know of things said the raids were related to hawala transactions.