An official warning about a council's child protection services was made several years before the deaths of five children known to the authority, it has been reported.
The BBC said the internal document from 2005 talked of "serious" problems at Doncaster Council's children's services department.
A second report two years later warned social workers were so overwhelmed that there were concerns for their mental health.
Five children who were known to Doncaster social services subsequently died during a seven-month period, the BBC said.
Last month Children's Secretary Ed Balls sent in a new management team to take over the leadership and management of children's services at the authority.
It followed a "thorough diagnostic review" of Doncaster's child safeguarding services ordered by Children's minister Beverley Hughes in January. As a result of the review, mayor Martin Winter said he would not stand for re-election.
According to the BBC, the report from 2005 said the re-organisation of Doncaster's children's services was not good enough to protect children.
And the report two years later, said to be more detailed, referred to details on vulnerable children "buried quite literally in a pile of other referrals".
Serious case reviews have been ordered into the deaths of seven children who died in the borough since 2004.
Managing director of Doncaster Council Paul Hart told the BBC: "Both the Government and the council are committed to making rapid improvements within the service and will take all necessary decisions to achieve the improvements."
