Dutt, CBI inspector Rajesh Chander Karnatak, alleged middleman Rajesh Pachisia and businessman Dinesh Chand Gupta -- arrested by the probe agency yesterday -- were remanded in CBI custody till May 21 by a court here today.
In its FIR lodged under the Prevention of Corruption Act and 120-B (criminal conspiracy) of the IPC, CBI said it had got an information that Dutt, a Superintendent of Police, was indulging in "undesirable activities" in connivance with Pachisia, who is having a business of computer software, and others.
It also said Pachisia had visited Dutt's office several times in past without making any entry in visitors' register as the visits were facilitated by the senior CBI officer.
Pachisia had impersonated himself as one Vijay from Malviya Nagar for gaining entry in the CBI's office, the FIR said, adding that Dutt had asked Pachisia to be careful while talking to him on phone and to introduce himself as Vijay as his phone might be on surveillance.