The EC ordered postponement of elections to the Rajrajeshwari Nagar assembly seat in saying there is "definite inference" to suggest that efforts were made to induce voters, PTI reported.
The counting for RR Nagar assembly poll will be held on May 31. The decision comes days after nearly 10,000 voter identity cards were recovered from a flat in the constituency.
The Election Commission on Wednesday had filed a First Information Report (FIR) on finding counterfoils and 9,746 voters ID cards in the Raja Rajeshwari Nagar Assembly seat in the southern suburb.
On preliminary verification, the voter cards were found to be genuine, while the counterfoils were to be verified through investigation, Kumar said. Five laptops and one printer were also found in the apartment, he added.
Election will now be held in Karnataka on May 12, in 222 constituencies out of 224 of the Karnataka Legislative Assembly.
Election has already been postponed in one constituency following the death of B.N. Vijay Kumar, Jayanagar BJP candidate.
The counting of votes and announcement of result will take place on 15 May 2018. The two opposition parties, Bharatiya Janata Party (42 seats) and Janta Dal (S) (29 seats), along with their allies, will take on the incumbent Indian National Congress (119 seats), while Aam Aadmi Party will mark its debut in the state.