Social services bosses say lawyers advised them that they "couldn't have appealed" when a senior family court judge ruled that Ellie Butler should return to live with the father who had been accused of hurting her.
Bosses in the London Borough of Sutton said they had "strongly contested" the decision made by Mrs Justice Hogg four years ago after a hearing in the Family Division of the High Court in London.
But a spokesman said lawyers had advised that there were "no grounds" for a legal challenge in the Court of Appeal.
Ellie died in October 2013 aged six after being found injured at her home in Sutton, south west London - about a year after Mrs Justice Hogg ruled that she should return to parents Ben Butler and Jennie Gray.
Butler was convicted of murdering Ellie in June 2016 after a trial at the Old Bailey - and given a minimum 23-year jail term.
Gray, was sentenced to 42 months in prison after being convicted of child cruelty. She had admitted perverting the course of justice.
A Sutton Council spokesman released a statement relating to lawyers' advice about Mrs Justice Hogg's decision after more detail about events leading up to Ellie's death emerged.
"Sutton Council strongly contested the decision that was made by Mrs Justice Hogg in 2012," said the spokesman.
"We sought legal advice but were advised there were no grounds for appeal."
He added: "We were advised we couldn't have appealed."
A number of family court judges, including two High Court judges based in the Family Division, oversaw hearings relating to Ellie.
Butler had been convicted of shaking Ellie when she was a baby - before being cleared on appeal.
The little girl had been placed with grandparents after Butler was accused of shaking her.
Following his appeal Mrs Justice Hogg re-analysed issues at a hearing in the Family Division of the High Court in London.
She published a ruling in October 2012, after concluding that Ellie should be returned to the care of Butler and Gray.
More detail about the case emerged on Friday when another ruling made by a different family court judge was published.
Mrs Justice Eleanor King had analysed issues - at another hearing in the Family Division of the High Court in London in 2014 - after Ellie had died but before Butler was convicted of her murder.
She had been asked to make findings to help Sutton Council social workers take decisions about Ellie's younger sibling's future.
Her ruling had been kept under wraps until criminal proceedings ended.
Mrs Justice King, who is now a Court of Appeal judge, had concluded that, on the balance of probabilities, Butler was ''responsible for Ellie's death''.
The judge said Ellie had suffered a skull fracture.
She said Ellie had moved from the "tranquillity and calm" of her maternal grandparents' home to a "toxic and abusive" atmosphere in her parents' home.
Copyright (c) Press Association Ltd. 2016, All Rights Reserved.