KNP officials said a group of about seven poachers had entered the park, famed for one-horned rhinos, last night and fired on a group of patrolling forest guards in Bornoloni camp under Bagori range.
The forest guards retaliated in which one poacher was killed while the others managed to escape.
Forest officials, however, suspect that some of them may have been injured.
Three .303 rifle, 16 rounds of live cartridges, mobile phones, ATM cards, a phone directory, shoes and other articles were found during subsequent search operations.
Search is on to nab the other poachers, they added.
