Investigators have discovered new evidence in the case of the suspected rape and murder of a 14-year-old girl in Kampot province, as the authorities continued to search for a second suspect in the brutal attack.

On Monday evening, victim Khun Nay disappeared from her house in the Lboeuk commune of Chhouk district, and on Wednesday morning at 6am, her mutilated corpse was found by her elder sister in a rice field a few hundred metres from the victim’s house, with grotesque injuries to her neck and face.

Yesterday, James McCabe, director of the Phnom Penh-based Child Protection Unit, which is assisting Kampot police in the investigation, said the authorities believed a bloodied palm frond found at the crime scene on Wednesday to be the murder weapon.

“[Nay’s] injuries were extremely brutal,” he said. “Something hardened crime investigators [involved in this case] haven’t come across in recent history.”

Authorities were initially looking for a samurai sword when they found the over 1-metre-long palm frond, said McCabe.

“It’s basically like a sword . . . serrated on both sides,” he said.

McCabe added that blood found on the frond tested positive as human yesterday. The remaining samples would be sent to Vietnam for DNA testing, he said.

“We’re searching for the offender. Whether there is one or two is not fully established. We must keep all investigatory options open,” he said.

The first suspect in the case, a 17-year-old neighbour detained on Wednesday, has not yet been charged, but is being held and questioned by police in Kampot, said deputy provincial penal police chief Kong Sakhon. The suspect lived near the victim and a shoe found inside the 500-metre-long crime scene was suspected to be his.

According to Sakhon, a second suspect, whom he would not name, has been identified by police and is believed to be a neighbour of the victim.

Lboeuk commune police chief Min Phal said the second suspect was “around 16 or 17 years old. We have made him a suspect because he often came to charge his phone at the house of the victim’s sister, and also they sometimes drank together.”

On Wednesday, the day the victim’s body was found in the rice field mutilated, the suspect left for Phnom Penh, apparently to work on a construction project, said Phal, who added that the two teenaged suspects were known to spend a lot of time together.

Phnom Penh police are working in collaboration with Kampot officers to find him.