The criminal investigation into a father found to have sexually assaulted his 13-month-old daughter shortly before her sudden death must be reopened, a former justice minister has said.
High Court family judge Mr Justice Peter Jackson ruled that 48-year-old Paul Worthington - on the balance of probabilities - "perpetrated a penetrative ... assault" on daughter Poppi but he will not face criminal action unless new evidence comes to light.
Sir Simon Hughes said the "very fact" the judge had made the findings public "must give cause for the authorities who deal with criminal matters to look again at the evidence".
The Liberal Democrat said "justice demands" that the original decisions in the criminal investigation are reviewed and called for the Crown Prosecution Service to reopen the case.
He told BBC Radio 4's Today programme: "I'm sure that they will review the case, I'm sure that that is the right thing that should happen. If the justice system is about not just justice for the deceased but to make sure that the welfare of the children who are still alive is best looked after, then it must be in the interests of justice that there is a review now as to whether there was any criminal liability for anything that led to the death of this poor little child."
Poppi collapsed with serious injuries at her home in Barrow-in-Furness, Cumbria, in December 2012 and was rushed to hospital where she was pronounced dead.
Cumbria Police conducted no "real" investigation for nine months, the judge found, as senior detectives thought a pathologist "may have jumped to conclusions" in her belief the child had been a victim of abuse.
The toddler was buried in February 2013, precluding a further post-mortem examination, after her body was released by the local coroner.
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.
Mr Worthington was arrested in August 2013 and questioned on suspicion of sexual assault but was not charged with any offence. He strenuously denies any wrongdoing.
The Crown Prosecution Service (CPS) has previously said it conducted "a thorough review of the evidence" but decided it was insufficient to provide a realistic prospect of conviction.