But hospital insiders allege Mrs Hale's bowel was ruptured because she fell from the operating table while under general anaesthetic just prior to the operation. They allege the fall also caused a minor head injury. The insiders claim there were no staff in the operating theatre when she fell. They allege Mrs Hale was told "a pack of lies" by hospital officials to conceal the truth.

It is alleged that once she was anaesthetised, a doctor and nurse left her unattended to work on another patient elsewhere in the hospital. When staff re-entered the room, it is alleged they found Mrs Hale hanging head first because her feet had been strapped to the table. When she hit the floor, a trocar - a hollow sharp cylinder used to introduce cannulas into blood vessels - that was inserted in her side had sliced through her bowel.

A source said: "It could so easily have killed her. "They had to open her belly up, remove the section of perforated bowel then stitch her back up and rush her to intensive care." Mrs Hale spent five days in hospital.

The Sun-Herald was told an internal critical incident report was compiled hours after the surgery, which stated Mrs Hale's injuries were sustained because she was left "unattended." On December 19, the same day The Sun-Herald began making inquiries, NSW Health Minister John Della Bosca was briefed that no such report existed. The hospital then told the minister, that same day, the report had just been compiled - a week after the incident. Mrs Hale said she was seeking legal advice. "This is absolutely not what they told me," she said.

"I was there because my appendix needed removing immediately. When I woke up, they said there had been 'complications'. They said part of my bowel had been removed because they discovered a small lump. They added it had been sent to a pathologist and it came back fine. I had a bump on my head. They said I hit that on a control panel." Mrs Hale said she wanted the truth. "I need to know what the lasting implications are and how this is likely to affect the rest of my life."

Hospital insiders said they chose to speak out because Campbelltown Hospital was providing the same "sub-standard care" that in 2003 had sparked the state's largest inquiry into patient care and safety standards. "It's become routine practice to leave anaesthetised patients unattended and to cover up negligence using any means necessary," the source said. Royal Australasian College of Surgeons executive director Dr John Quinn said: "I find the episode you are recounting almost non-tenable. Patients in a hospital operating theatre, who are given a general anaesthetic, are not left unattended. It just shouldn't occur."

Australian medical experts meanwhile have cast doubt on the hospital's version of events. Cancer Institute NSW head Jim Bishop said for a complex operation involving the removal of bowel cancer, it would be "very unusual" not to gain the patient's consent first.

Professor Bishop said it was common practice for doctors to first perform scans, biopsies and follow-up tests to see whether the cancer had spread and if so, how far. Director of Research at the Sydney Cancer Centre, Bruce Armstrong said: "Best practice would generally be to seek formal consent, from the patient … to inform them of what was found and to conduct further investigations." Medical Error Action Group spokeswoman Lorraine Long said: "Doctors and nurses are swamping our hotline with stories of negligence that make you want to cry."

Mr Della Bosca said the incident was being fully investigated. "If the family has concerns, we would urge them to contact the Health Care Complaints Commission. Alternatively, they can contact my office." Opposition health spokeswoman Jillian Skinner said: "This is one of the worse examples of patient care. To claim an internal report wasn't compiled until a week later is suspicious, to say the least."