Zilalluddin Ali Khan, the accused officer, was arrested while taking the money in his office here.
DSP V Gopalakrishna told PTI that the officer had demaded Rs 50,000 for Sales Tax assessment from the Digital cool Enterprises' owner D Yedukondalu.
Later the amount was negotiated down to Rs 15,000, with the help of Commercial Tax Office Senior Assistant B S Prasad, after which Yendukondalu approached the ACB which set a trap and arrested Khan. Prasad too was arrested. Further probe is on.