Police said according to a note left by the ultras, Gopinath Lima (35), a resident of Bhurukuda village under Gudari police station, had played a crucial role in the arrest of Maoist commander Uday, who too hailed from the same village.
The police, however, denied that Gopinath was their informer.
Four Maoists fired two rounds at him from point blank range while he was returning from a field this afternoon, villagers told the police. The note recovered from the spot also cautioned land lords and money lenders to refrain from exploiting the poor, the sources said.