Toddler Poppi Worthington was sexually abused by her father shortly before her sudden death, a family court judge has ruled.
The 13-month-old was found with serious injuries at her home in Barrow-in-Furness, Cumbria, and rushed to hospital, where she was pronounced dead in December 2012.
Her father, Paul Worthington, 47, was later arrested and questioned on suspicion of sexual assault but never charged with any offence. He denies any wrongdoing.
However, High Court family judge Mr Justice Peter Jackson, sitting at Liverpool Crown Court, ruled that - on the balance of probabilities - Mr Worthington "perpetrated a penetrative ... assault on Poppi".
The little girl's death had been shrouded in secrecy, with a 2014 fact-finding civil court judgment being kept private so as not to prejudice any criminal proceedings, while an inquest controversially took only seven minutes to declare her death as "unexplained".
Last month, three medical experts gave evidence in open court stating that they disagreed with the findings of a Home Office pathologist who carried out a post-mortem examination on Poppi and believed she was the victim of "a penetrative sexual assault".
The hearing took place after Mr Worthington appealed against the 2014 findings of Mr Justice Jackson as part of care proceedings in relation to other children in the family.
Those findings were published in full for the first time today, and also ruled that Mr Worthington carried out a sexual assault.
Mr Justice Jackson said that, following the review of medical evidence, he found no reason to come to a different conclusion and dismissed Mr Worthington's appeal.
In his fresh judgment, Mr Justice Jackson said: "In conclusion, stepping back and reviewing the evidence as a whole, I arrive at the same view as I expressed ... of the previous judgment.
"Shorn to its essentials, the situation is one in which a healthy child with no medical condition or illness was put to bed by her mother one evening and brought downstairs eight hours later by her father in a lifeless state and with troubling injuries, most obviously significant bleeding...
"Careful assessment of the meticulous pathological and paediatric evidence has clearly established that the injuries were the result of trauma from outside the body.
"My finding (in the previous judgment) was that the father perpetrated a penetrative ... assault on Poppi ... That remains my conclusion."
It emerged previously that senior detectives thought pathologist Dr Alison Armour ''may have jumped to conclusions'' when she raised suspicions about Poppi's death as they decided not to investigate until the full post-mortem report was ready - but it was not finished until the following summer.
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 examination the youngster was found to have an earlier fracture of her right lower leg and suspected acute internal injuries.
Among the police omissions were items not being preserved for forensic analysis either at the home or at the hospital after Poppi's collapse and the scene at the house not being secured.
The toddler was buried in February 2013, precluding a further post-mortem examination, after her body was released by then local coroner Ian Smith.
There is now said to be an "absence of evidence'' to find out how Poppi died or definitively prove if or how she was injured following the botched police investigation and her burial. All the medical experts who have reviewed the case agree the cause of death is "unascertained".
Cumbria Police announced in March last year that no charges would be brought against anyone over Poppi's death, including her mother, who cannot be named for legal reasons.
The mother wept in court as Mr Justice Jackson gave a summary of his fresh judgment.
Mr Worthington did not attend the hearing.