Senior officials "deliberately delayed" carrying out child protection measures to help Bury Council's ruling Labour group before an election, reports say.
Reports seen by the BBC state former chief executive Mike Owen and head of children's services Mark Carriline failed to act quickly enough after claims were made against a councillor.
Simon Carter later admitted 16 charges of making indecent images of children.
Mr Owen apologised for any errors but denied any political motivation.
'Inexplicably' delayed procedures
Mr Carriline could not be contacted while Mike Connolly, the former council leader, declined to comment.
At an extraordinary meeting later, Bury councillors will vote on whether to publish the results of two independent reports into the council's handling of the situation.
The contents of those reports have, however, been seen by the BBC.
They found Mr Owen and Mr Carriline had "inexplicably" and "deliberately" delayed implementing safeguarding procedures when allegations about Carter first came to light in the spring of 2015.
The then Tottington councillor was on the adoption register at the time.
Later that year, Carter was given a three-year community sentence and placed on the sex offenders register for five years, at Bolton Crown Court.
Although Carter was immediately removed from the council's list of people approved to adopt children, the reports found Mr Owen and Mr Carriline waited up to five weeks to carry out a string of child protection measures that should have been implemented within 48 hours of the allegations being made.
That included taking eight days to inform the two schools where Carter was a governor.
Mr Owen demonstrated a misguided desire to "help" Mr Connolly, investigators concluded, which manifested itself in inappropriate briefings, a desire to control the proper flow of information and a failure to adhere to the council's policies and procedures.
The disciplinary panel concluded this was a misguided attempt to protect the former administration and its leader Mr Connolly from public scrutiny in the run-up to the 2015 elections.
In relation to Mr Carriline, the disciplinary panel found he was overly compliant to Mr Owen and, in so doing, lost sight of his statutory duties.
Mr Owen told the BBC that he accepted his position as chief executive was "untenable irrespective of the outcome of the [disciplinary] hearing".
He said he had always denied "any deliberate wrongdoing", adding he was "truly sorry" for making "procedural errors of judgment".
He "absolutely refuted abhorrent allegations" that his actions were intended to "help [Mr Connolly] and to impact the result of the election".
Mr Connolly, who is still a councillor, told investigators he had been wrong to give Carter a written reference on council-headed notepaper ahead of his sentencing, describing him as "trustworthy, honest and reliable".
Mr Connolly refused to comment when contacted by the BBC.