Singh, a 1985 batch IPS officer of Kerala cadre, was shifted from the anti-corruption branch of the agency to the economic offences wing on Thursday, a day after the CBI filed its first chargesheet in the Adarsh scam against 13 accused including former Maharashtra chief minister Ashok Chavan.
Though the CBI has maintained that it is a routine transfer, Tawde's letter seeks to question the timing of the move.
Keshav Kumar, a 1986 batch IPS officer from Gujarat cadre, will take over from Singh.
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