A judge will rule on whether a father sexually abused his 13-month-old daughter shortly before her sudden death.
Poppi Worthington 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 arrested and questioned on suspicion of sexual assault but never charged with any offence. He denies any wrongdoing.
The death of the toddler 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 they disagreed with the findings of a Home Office pathologist who believed Poppi was the victim of "a penetrative sexual assault".
The hearing took place after Mr Worthington appealed against the 2014 findings of High Court family judge Mr Justice Peter Jackson - based on the balance of probabilities - as part of care proceedings in relation to other children in the family.
Parts of those findings were published for the first time before the hearing got under way. It revealed that Cumbria Police conducted no "real" investigation into Poppi's death for nine months.
It emerged that senior detectives thought pathologist Alison Armour "may have jumped to conclusions" when she raised suspicions about the 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 the youngster was found to have an earlier fracture of her right lower leg and suspected acute injuries in the region of the anus.
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 youngster 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".
Lawyers representing Mr Worthington told Mr Justice Jackson last month their client was a "doting and loving" father and there was "no sufficient evidential basis'' to suggest he abused his daughter before her death.
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 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 force referred itself to the Independent Police Complaints Commission and said three officers were subject to the investigation - with the suspension of one officer, who has since retired, while the others had moved into different roles.
Last July, High Court judges ruled a second inquest should take place.
Mr Justice Jackson will hand down his fresh fact-finding judgment at Liverpool Crown Court on Tuesday.