The FIR was lodged against "some ministers and MLAs" without naming anyone under various sections of Prevention of Corruption Act and Representation of the People Act.
"We will identify the persons involved in the alleged incident after verifying evidences given by the state government," the sources said.
The case was registered at the Capital police station here on the basis of a complaint made by S N Pradhan, deputy secretary in the home department.
"We have instructed the police to investigate the matter according to the direction of the Election Commission," Home Secretary U N Behera told reporters.
The issue of horse trading in Rajya Sabha polls was raised after ruling BJD won all the three vacant seats in the Rajya Sabha though it lacked the required number.
The matter rocked the state in June after a local TV channel telecast an audio-CD where a person, alleged to be a state minister, was speaking to a middle man regrading the RS poll. The middle man was said have worked on behalf of a Congress MLA who allegedly abstained from voting in the RS polls held on June 17, 2010.
BJD`s third candidates won the polls as two MLAs from Congress and one from BJP abstained from voting. Meanwhile, Congress and BJP have suspended one MLA each from their parties for abstaining from voting defying party whip.