A "substantial question mark" hangs over the evidence used to convict four people of killing or harming babies by shaking them, the Court of Appeal has heard.
Three men and one woman, jailed for the murder, manslaughter and grievous bodily harm of young children, are attempting to have their convictions overturned in a test case that could have repercussions for around 90 other cases of "shaken baby syndrome".
Mike Mansfield QC, who is representing the four - Raymond Rock, Alan Cherry, Michael Faulder and Lorraine Harris - told the court: "There is no suggestion that any of these carers were child abusers. The evidence was the reverse - that they did care and were loving and supportive."
All four trials had been dominated by expert evidence, Mr Mansfield said. In Mr Rock's case, the evidence of seven key prosecution witnesses had included phrases such as "I have never seen such severe injuries", "shaken as hard as you can", "nothing short of full-force shaking", and "equivalent to a high-velocity road traffic accident". The jury was left with little alternative but to convict, he said, even though none of the evidence offered objective medical proof that there had been violent treatment.
Mr Mansfield said new scientific evidence suggested the convicted parents or carers may have been telling the truth, and "a substantial question mark" had been placed over their convictions.
"This is not back-room biology by a few cranks," he said. "These are highly reputable experts from different institutions in the UK and some in the US who therefore do not espouse something which is fanciful."
One could not perform experiments on the living brain of an infant to discover what actually happened when varying degrees of force were used, Mr Mansfield said, adding: "No one actually knows the level of force required to produce one or more of the triad of features seen." This "triad" - swelling of the brain, bleeding between the brain and the skull and bleeding in the retina of the eyes - which is regularly claimed to be evidence of "shaken baby syndrome" could no longer be relied on, he said.
There was now "a substantial body of opinion" that "a far lesser threshold of force" could have caused the injuries than previously thought, he added.
The question for the court was "whether the jury could safely convict" when there was now an alternative hypothesis to that relied on by the experts who had helped obtain convictions at trial.
Richard Horwell, for the prosecution, told the judges Mr Mansfield's argument was flawed.
The case stems from a review of some 300 infant death convictions, including more than 90 involving shaken baby syndrome, ordered by the Attorney General, Lord Goldsmith, after Angela Cannings successfully appealed against her convictions for murdering her two baby sons.
Mrs Cannings was cleared in 2003 after judges ruled that no one should be prosecuted solely on the basis of medical opinion which was the subject of disagreement between experts.
The outcome could also affect hundreds of Family Division cases in which a parent has been denied access to a child on the basis of allegedly violent treatment.
The hearing continues.
Convictions that may be overturned
* Raymond Rock, of Great Yarmouth, Norfolk, is serving a life sentence for murdering his girlfriend's 13-month-old daughter, Heidi Davis, in 1998. He insisted she wriggled out of his arms and fell to the floor.
* Alan Cherry, 54, of Birmingham, was convicted in 1995 of the manslaughter of his girlfriend's 22-month-old daughter, Sarah Eburne-Day. He claimed she fell off a stool. Since released.
* Lorraine Harris , 36, of Long Eaton, Derbyshire, was jailed for the manslaughter of her four-month-old son, Patrick McGuire, in 2000. She said the baby became ill and stopped breathing after a vaccination. She was released from prison but was banned from seeing her other child.
* Michael Faulder, 34, of Gateshead, was jailed for two and a half years in 1999 for causing grievous bodily harm to a boy aged seven weeks. He said he accidentally dropped the baby while trying to put him in his pushchair. The boy made a full recovery.Reuse content