The CBI on Monday arrested four senior income tax officials, including commissioner investigations Kanpur range Kunal Singh, and managing director of realty firm Eldeco in connection with an alleged graft case.

The agency arrested IRS officer Kunal Singh, joint director investigations Ratan Singh, also an IRS officer, assistant commissioner Uma Kant and income tax inspector Harish Daundiyal, CBI sources said.

Pankaj Bajaj, managing director of realty firm Eldeco which is under the scanner for alleged tax evasion, and chartered accountant Anil Jaiswal were also arrested by the agency during the operation, they said.

Repeated attempts to call Eldeco did not materialise. The e-mails sent on the ID given on the group's website bounced back.

The action comes after searches conducted by the CBI last night at several locations, CBI sources said.

Sources said based on a tip-off that the officers were allegedly accepting bribe to settle a tax-evasion cases, CBI had carried out searches at various locations.

Kumal Singh, who was heading the probe and criminal investigation units of the I-T, along with his team had recently conducted search operations against officials of the Greater Noida authority and private real estate players besides carrying out I-T raids in Uttar Pradesh and in the national capital region.