Separate teams raided the residence of the official here and at least six other places, a senior CBI official said.
The CBI, which had on June 20 lodged an FIR after the High Court asked it to probe the miserable electricity situation in the state, allegedly found low quality transformers.
More than 800 transformers were purchased at a cost of Rs 16 crore in 2011-12, the official said quoting the FIR.
The raiding teams seized several documents and computer records.