The arrested person was identified as Pradip Singh and according to CBI sources, he acted as a middleman between the scamsters and the candidates.
A 12-member CBI team raided the NBU vice-chancellor's office in Siliguri, the largest town in the northern part of the state.
Both were named in the FIR filed by CBI before starting its investigation in the matter.
The central agency sleuths recovered huge treasures for the first time on July 22 from the Tollygunge residence.
Also, Trinamool Congress's daily party mouth piece in Bengali, Jago Bangla (Wake up Bengal) has stopped referring to Partha Chatterjee as the state minister or the party secretary general, since the time he had been arrested by ED.
The ED is "keeping a close eye" on some people of Odisha and Tamil Nadu and may soon grill them, the agency official explained.