IN 1998, one of the world’s leading psychologists, Professor Elizabeth Loftus, turned detective. She wanted to find out the identity of a girl whose story was at the heart of an important scientific paper. Loftus was suspicious of the story, but could only confirm her suspicions if she could pierce the anonymity of the girl called “Jane Doe” in the paper. If her hunch was right, she would be able to destroy one side of the argument in what has been called “the memory wars”.

Her hunch, it seems, was right, but it has led her into a minefield of disciplinary hearings and a lawsuit.

Over the past 15 years, a school of social workers and psychotherapists has emerged who believe that memories of child abuse can be repressed in childhood and then revealed years later, during psychotherapy or medical interviews. This belief has led to a series of major court cases, in this country and in the US, and Loftus has been an important scientific expert in some of these cases, presenting evidence that “false memories ” of abuse were often created by the aggressive questioning of people who already believed that abuse had taken place.

The accusations last month against Michael Jackson are based, like an earlier accusation, on “memories” of abuse that emerged during a child’s encounter with a therapist. In the first Jackson case, the accusations emerged only after a child was put on an intravenous drip of the drug sodium amytal, formerly believed to be a “truth drug” but now known to enhance a patient’s suggestibility.

Loftus, an elegant woman in her fifties with uncontrollable hair, speaks intensely about the rash of law cases. She has been an expert witness or consultant on a wide range of cases in which the fallibility of human memory has been a central issue, including the trial of Oliver North, the Rodney King beating, the Menendez brothers case and the first Jackson case. But it is her work on “false memory” that she is most proud of, helping to overturn charges of sex abuse against carers and parents, based solely on the statements of very young children or on so-called “recovered memories” of adults.

“They were one of the major mental health scandals of the 20th century,” she says. “We saw thousands of lawsuits — all that money, all that waste, all that pain.”

Loftus has been showered with professional awards over the years for a series of pioneering experiments that show the unreliability of memory. One of her achievements has been to cast doubt on the idea of “repressed memory”, by which traumatic events are so deeply submerged in the mind that they are impossible to retrieve for many years. “The opposite is usually the case,” Loftus says. “When people have been abused in childhood their problem is not that they can’t remember, but that they can’t forget.”

But she has come up against strong resistance from those who cling to the belief that there is such a thing as repressed memory, the idea at the heart of the case that she tried to investigate. And it may be that resistance that has led to an action against her by her university for unethical behaviour, and a lawsuit for invasion of privacy by Jane Doe.

The case that is the cause of Loftus’s troubles was reported in a medical article in 1997. A psychiatrist from Cincinatti, David Corwin, wrote a paper in which he described the case of a child he called Jane Doe. Corwin had been called in as an expert in a custody dispute and he said that his case history proved that memories of abuse in childhood could be completely forgotten and then surface years later. He had interviewed Jane several times when she was five and six, recording one of his interviews on videotape. On the tape, Jane is seen describing various abuses at the hands of her mother, including violence and sexual molestation. Corwin then reinterviewed Jane when she was 17 and says that memories of the abuse came flooding back to her after having been entirely forgotten for 11 years. When Corwin showed these videos at academic conferences they caused quite a stir, bringing tears to the eyes of some members of the audience.

“Therapists began to use the case as proof of repressed memory,” Loftus says. “Psychologists began to teach the case in their classes. Lawyers began to cite the case in court during the prosecution of other individuals charged with sexually abusing their children.”

Corwin’s case seemed to prove that “repressed memory” was possible. This was important because it allowed accusers to bring up grievances that had occurred many years before, perhaps 30 or 40, when normally such old accusations would be excluded. “You could now say, ‘I repressed the memory’,” Loftus says. “ ‘I could have had no access to it. It was walled off from the rest of my mental life, and only after I went into therapy and felt safe and was able to retrieve all this information did it come back, and therefore I should be allowed to sue’.”

There were two things about the Jane Doe case that worried Loftus. She had never come across a watertight example of truly repressed memory, and this didn’t seem to be one either. And from what she read in Corwin’s report she didn’t even think that there was very strong evidence that Jane Doe had been abused at all. But she couldn’t check the facts unless she knew Jane Doe’s identity, and Corwin had protected her identity by removing from the report everything that might reveal it. Normally, a scientist reading such a report would see no need to try to “break the code”, as Loftus did, since on the whole if data are published in a reputable journal, you normally trust the research. But what do you do if you have reasons for doubting the data? Suppose an eye specialist published an anonymous case history of someone who had X-ray vision.

Wouldn’t it be legitimate to track down this amazing person to see if it was true? Loftus had no intention of revealing Jane Doe’s identity to the world, but she certainly felt that it was justified to investigate the facts of her case and see if they were what Corwin had reported.