Prawit Saengsakul, the head of management area 3 (Lam Plai Mat) of the park, on Saturday led a team of veterinarians to examine the carcass of the female elephant, aged over 40 years old, on the plantation in tambon Non Somboon of Soeng Sang district, about 400 metres from the park boundary.
Local residents alerted park officials after finding the dead jumbo on Friday morning.
Vets found more than 10 stab wounds on the body of the female pachyderm. The largest wound was in the head.
Traces of a struggle and footprints of the two elephants were scattered over the area. The vets believe the attacker was a male elephant living in the area.