The operation, which was conducted by the Suame Service Centre of the company, was in areas such as Kronum, Afrancho and Kwapra.
Briefing the press, the Ashanti Regional Communications Manager of ECG, Mr Erastus Kyere Baidoo, said all those arrested were people who were disconnected for non-payment but reconnected themselves illegally.
He said the offenders were mainly residential users, enterprises and churches.
The churches involved in the illegal connections were Church of God at Kwapra and Holy Church of the Lord at Kronum.
According to him, all the 12 offenders owed collectively GHC150,000
He said in all, the debt owed the company in the region stood in the region of GHC130million and asked those who were owing to take steps to settle their debts or have their power disconnected.