This undated photo provided by the Facebook group HelpAndrewOberle shows US graduate student Andrew Oberle sitting near a chimp. Doctors are reporting improvement in the condition of Oberle, who was attacked by chimps while studying in the country. Picture: AP

African Eye News Service and SAPA-AP

The Mpumalanga Tourism and Parks Agency has found no gross negligence on the part of Chimp Eden where two chimpanzees attacked an American student.

Lead investigator Dries Pienaar said that anthropology student Andrew Oberle, 26, climbed over a 1.2m safety fence and placed his foot on a rock next to the electric fence.

“That is when the chimps grabbed his foot and pulled him under the fence.

“This tripped the electric fence that had 9 000 to 12 000 volts running through it,” Pienaar said.

The investigator said he was amazed by how much damage the two chimps, aged 15, had done.

Oberle suffered several fractures, while large pieces of flesh and muscle, including one of his testicles, were torn from his body.

“They tore all the clothes from his body, there was hair and blood everywhere, and they ripped out one of his testicles,” said Pienaar.

“I know the chimps and never thought they could be capable of this.”

Although the chimps grew up in captivity and were among the first males to be introduced at Chimp Eden for rehabilitation five years ago, they remained wild animals, he said.

Pienaar believes the chimps must have felt threatened when Oberle crossed the fence and that they acted to defend their territory.

“That is why rocks are placed under the fence line to prevent turtles or meerkats from entering the camps.

“The chimps will rip them apart,” he said.

Pienaar said the two primates, called Nikki and Amadeus, were in such a state of aggression that they almost smashed the windscreen of handlers Eugene Cussons and Phillip Cronje who tried to use a vehicle to chase them away from Oberle.

“That is when Eugene had to shoot at Nikki with his 9mm. It was the only way,” said Pienaar.

Cussons said Amadeus had calmed down since the incident. Nikki had been taken to the Johannesburg Zoo for treatment.

“We have also started trauma counselling of all our staff and tourists who witnessed the event,” said Cussons.

Both Cussons and Pienaar have confirmed there is no need for the chimps to be put down.

Oberle, a student from the University of Texas in San Antonio, came to SA last month to work on his Master’s degree in Anthropology.

Cussons said Oberle wanted to collect data and study the behaviour of the primates as part of his degree.

Oberle’s family arrived in Mbombela on Monday after travelling from the US.

The student was still heavily sedated after undergoing six hours of surgery.

“The family has just arrived and will first see their son… but at the moment they don’t want to talk to the media and hope the media will respect their privacy,” Medi-Clinic spokeswoman Robyn Baard said.

A plastic surgeon was part of the team that cleaned Oberle’s wounds and repaired the fractures.

“The patient is in a stable condition but under induced sedation to ease the pain,” she said.

Yesterday the hospital said the student remained sedated after surgery to clean his wounds and deal with his injuries. He was still in intensive care.

Oberle had been placed in an induced coma “because he lost so much blood and his blood pressure was so low”.