Angelique Todd, a former keeper at the zoo, was feeding three chimps at lunchtime on Sunday when Bustah, a 33-year-old male chimpanzee, grabbed her coat and pulled her arm into the cage.
She was taken to the William Harvey Hospital in Ashford before being transferred to the Queen Victoria Hospital in East Grinstead, West Sussex.
Ms Todd was feeding Bustah and two elderly female chimps voluntarily. She is keen to work with apes and chimps in Africa and has spent a lot of time at Port Lympne in the past three years as a volunteer and keeper. Yesterday a spokesman for the Queen Victoria Hospital said he was unable to say how she was because her parents had asked him not to comment on her condition.
Mike Lockyer, zoological director of Port Lympne and Howlett's Zoo, Mr Aspinall's other zoo near Canterbury, said that Ms Todd had been throughly trained and was considered a competent person to feed the chimps. He added that there might have been 'an element of human error' - she might, for example, have been concentrating on one animal rather than another.
He said fully mature male chimpanzees were 'highly dangerous'. They are seven times stronger than a human, have lightning reactions and a very volatile temperament. It was quite wrong to think of them as the cuddly creatures portrayed in P G Tips advertisements.
In March 1989, Matthew McDaid, of New Eltham, south London, ducked under a safety chain at the zoo and got so close to Bustah's cage that the chimp pulled his arm off. While John and Frances McDaid comforted their son, Bustah prowled around with the limb until keepers retrieved it by sedating the chimp with a tranquilliser dart.
Matthew, now 7, lost his left arm and has difficulty doing up buttons and zips, cutting his food, holding things and playing sport. His parents are suing Mr Aspinall, an animal lover and casino owner, for negligence because they argue that the safety barriers were not adequate.
Mr Lockyer said that there was a world of difference between the two incidents involving Bustah. One involved a fully trained adult authorised to be feeding the chimps, the other involved a child in the wrong place outside a public viewing area.
Mrs McDaid said yesterday that there was 'no way he (Matthew) should have been allowed to get that near. It was negligence on the zoo's part to let him get anywhere near there'. She conceded that the latest incident involving Ms Todd, a former keeper, did not, however, appear to be comparable.
Over the past 25 years there have been a number of incidents at Mr Aspinall's zoos in Kent. In 1980, two keepers were killed by a Siberian tigress in separate incidents at Howletts and in 1984 another keeper was crushed to death by a bull elephant at Port Lympne.
The latest mauling at Port Lympne is being investigated by environmental health officers at Shepway District Council. Mr Aspinall, who was at Howletts yesterday, was not available for comment.