According to police sources, they received a tip-off that the sitting MLA, accompanied by two alleged criminals, Jaiprakash Bhuiyan and Rajkamal Gope, was returning to Khunti from Ranchi by a car.
A police team headed by Karra police station in-charge Hardeo Prasad asked them to stop for checking on March 28, but they did not do so, they said.
Yesterday, a case was registered under IPC sections 212 (harbouring offenders) and 216 (harbouring offenders who have escaped from custody or who were facing arrest).
Ekka, a former minister, facing charges in a money laundering case, is out on bail.
Khunti goes to the polls on April 17.