The first chimpanzee to join Sierra Leone's reserve for the animals is believed to have turned killer and is still at large, rangers warned.
The 20-year-old animal, named Bruno, has been linked to the death of Sierra Leonean driver Issa Kanu, zoo officials said Tuesday.
Two US tourists were seriously injured during an attack by a pack of chimpanzees on the loose at the Tagucama Chimp Sanctuary on the outskirts of Freetown.
Sierra Leonean police and rangers continued Tuesday the hunt for Bruno and 17 other chimpanzees after only nine of the 27 that escaped from the reserve had been recovered.
According to zoo officials, citing survivors' accounts of the attack, Bruno smashed with his fist the windscreen of the car which took the men to Tacugama.
Kanu tried to drive the car away but crashed into the zoo gate and the vehicle was trapped by the iron bars.
"Bruno grabbed the driver by the neck, slammed him on the ground and chopped off all his fingers and toes," one official who asked not to be identified said.
"He then ate up the entire face of Issa leaving him dead,"
Sanctuary manager Bala Amarasekaran said, he bought Bruno when he was a few months old for 30 dollars and named him after Frank Bruno, the British heavyweight boxer who fought Mike Tyson the day of the transaction.
According to the Tacugama official website, for a year Bruno lived in the Amarasekaran house but "got up to lots of mischief".
Described as the "alpha male", Bruno "is a large, powerful chimp."
"He is wary of visitors and is painfully accurate at hurling rocks and stones at anyone he doesn't like the look of."
He was only moved into a cage when a second chimpanzee was acquired.
"One of the most wanted chimps is still at large, we are hoping that he could be caught quickly," a zoo keeper told AFP Tuesday.
Sama Banya, president of the Sierra Leone Conservation Society which runs Tacugama, said the weekend attack was the first of its kind in the 10-year history of the sanctuary.
He said the primates "are not wild but their behaviour was highly unusual" at the time.
The names of the injured Americans have not been officially released but media named the three people in the group besides Issa as Alan Robertson, Gary Brown and Richie Goodie.
They were all American sub-contractors working at the site of the new US embassy under construction at Leicester Peak Junction some three kilometres (about two miles) from the zoo.
A nurse at the hospital told AFP: "The men are recovering gradually from shock and their wounds are no longer life-threatening."