The sudden, unexplained death of a 13-month-old girl who may have suffered a sexual assault presented a "very, very worrying picture," a court heard today.
Poppi Worthington died after being found by her father with a serious injury at her home Barrow, Cumbria, in 2012.
Her father, Paul Worthington, 47, was later questioned on suspicion of sexual assault but never charged with any offence. He denies any wrongdoing.
But Cumbria Police's shambolic investigation afterwards left a catalogue of failures. No-one has ever been charged, and the sudden death of the normally healthy youngster remains "unascertained".
The circumstances were kept secret by officials until the press took the matter to court, and Mr Justice Peter Jackson agreed that "as much information as possible" should be made public.
His report on the facts of the case was published for the first time yesterday.
It revealed what has been called "astonishing incompetence", showing how police made 12 basic errors, including failing to collect evidence, interview witnesses or question her parents, and only beginning to investigate nine months after the girl died.
Senior detectives in Cumbria thought a pathologist "may have jumped to conclusions'' when she first raised suspicions about injuries to Poppi's anus.
They decided not to investigate until the full post-mortem report was ready, but this was not finished until the following summer.
By that time the body of the Barrow-in-Furness toddler had been released by the local coroner, Ian Smith, whose inquest into the "unexplained and possibly suspicious circumstances" around Poppi's death lasted just seven minutes.
In consequence, her body was buried in February 2013, precluding a further post-mortem examination. A second inquest has now been ordered by a senior judge.
Pathologists are still in dispute over whether Poppi suffered a sexual assault before her death.
In a hearing at Liverpool Family Court this week reviewing the medical evidence, the court heard that on December 12 2012 Poppi awoke screaming at around 5.45am, according to her father, and an ambulance was called.
On admission to hospital and at post-mortem the youngster was found to have an earlier fracture of her right lower leg and suspected acute injuries in the region of the anus, from which she was bleeding.
Dr Alison Armour, who conducted the first post-mortem examination on Poppi, said she believed the girl's injuries were caused by a "penetrative sexual assault".
Her "hypothesis" is disputed by other medical experts who reviewed the same evidence, but she has maintained her initial findings.
Today, the court heard medical experts disagreed on the interpretation of possible injuries and the bleeding Poppi suffered.
Dr Nat Cary, an expert forensic pathologist, who reviewed Dr Armour's findings, said he believed the pathological evidence was "entirely neutral" and did not point to a "penetrative sexual assault".
Jane Cross QC, representing Cumbria County Council, asked the witness: "This is what this case is about. A difference of respectable, professional opinion."
Dr Cary replied: "I would say that failure to take account of what colleagues have to say about a case is important when you are looking at difference of professional opinion."
Ms Cross continued: "This little girl, who was to all intents and purposes well, with a common viral infection... A little who girl who goes to bed, is heard to cry out and very shortly after that is collapsed, dies and has blood emanating from her anus, in a way that one doctor described as a wound, that is what he described. It's a very, very worrying picture isn't it?"
Dr Cary replied: "Absolutely."
Ms Cross said: "The issue of anal penetration is still one that can't be set aside is it?"
Dr Cary replied: "I think that's right."
Ms Cross added: "And it is entirely proper for her (Dr Armour) to be exploring the hypothesis of penetrative anal assault, isn't it?"
Dr Cary: "I think so, yes."
Ms Cross continued: "The fact of the matter is this: although you are taking issue with specific facts and interpretation of findings, you can't assist the court with an alternative cause for bleeding to Poppi's anus, can you?"
Dr Cary replied: "No."
Both parents deny causing any harm to their daughter.
Mr Worthington was informally interviewed by police in 1995 over his association with someone who may have committed offences against children.
In 2003, he was the subject of an unrelated allegation which was later retracted.
Cumbria Police announced in March this year that no charges would be brought against anyone over Poppi's death.
Yesterday, the force said "lessons have been learned" following Poppi's death.
The hearing was adjourned until Monday.