Calcutta: CBI special director Rakesh Asthana is scheduled to arrive in Calcutta on Tuesday to meet the agency's east zone heads, prompting some officers to wonder whether some politically sensitive files would be dusted off.

Asthana, a Gujarat-cadre IPS officer, is the agency's No. 2 after director Alok Verma, and his visit has become a talking point among CBI officers as well as politicians linked to the Saradha, Narada and Rose Valley cases.

"Such reviews are generally followed by instructions on the next course of action," an officer overseeing the Narada probe said.

A Trinamul leader said he was not surprised by the timing, seeking to link it to the political developments that have begun to gather momentum in the run-up to the general election next year.

On Monday, chief minister Mamata Banerjee returned to Calcutta from Delhi after having met a host of Opposition leaders, including Ahmed Patel of the Congress, in the capital.

Asthana, who handled several high-profile cases including the AgustaWestland VVIP helicopter scandal and the fodder scam in Bihar, is expected to meet officers from six units operating out of Calcutta at the CGO Complex in Salt Lake.

He arrived in Bhubaneswar on Monday evening to review the progress of investigations into several ponzi-scheme cases and is expected to reach Calcutta on Tuesday morning.

In April last year, the agency had drawn up FIRs against 13 people, including BJP leader and former Trinamul number two Mukul Roy and IPS officer S.M.H. Mirza, in the Narada case.

In the 14 months since, the agency has questioned only a handful of Trinamul politicians and Mathew Samuel, the journalist behind the purported sting that shows figures resembling well-known politicians accepting money.

In the Rose Valley case, the CBI had arrested Trinamul MPs Sudip Bandyopadhyay and Tapas Pal, besides group owner Gautam Kundu. Both MPs are out on bail.

In the Saradha deposit-default case, the agency had submitted three chargesheets before arresting Trinamul politicians Madan Mitra and Kunal Ghosh apart from group chairman Sudipta Sen and aide Debjani Mukherjee. Mitra and Ghosh have been granted bail.