The RR Nagar seat, as it is popularly known, was held by the Congress's N Munirathna, and the BJP alleged that he was behind the startling discovery that came days before the election. The Congress retorted that it was a "drama" staged by the BJP, whose supporters owned the flat.
In response to complaints from both sides, the Election Commission postponed the election. The BJP, which dubbed Mr Munirathna the "money bag" of the Congress, called the commission's order a "victory of democracy".
The subsequent tie-up between the Congress and the Janata Dal Secular pitted the new allies against each other.
Mr Munirathna has been named as an accused in the case related to voter ID cards, which involves election-related malpractices and under the Representation of the People Act.
Rajarajeshwari Nagar is one of the larger constituencies in Bengaluru and has about 4.71 lakh voters.