Sheffield Council could be ordered to pay compensation to the victims of ex-worker Roger Dodds.
Abuser Dodds was jailed for 16 years on Friday for sexually assaulting students and colleagues while he worked for the council between the 1970s and 1990s.
It took more than 30 years for him to be brought to justice, despite two investigations during his time at the authority.
Dodds, 81, of Cotswold Road, Hillsborough, was employed in 1975 to head the council's grants and awards department. He used his position to force teenagers to engage in sexual acts in order to secure payments.
He was investigated by the authority in the 1980s after complaints from colleagues, but was moved to a different post working with schools.
More allegations in 1993 led to a second investigation, after which Dodds was given an early retirement package.
An independent investigation, carried out after an accusation of historic abuse was made in 2008, found failures in how the council dealt with complaints against Dodds.
South Yorkshire Police investigated the complaints, but the Crown Prosecution Service, or CPS, did not press charges.
A CPS spokesman said its files did not contain details on why that decision was taken.
Dodds was eventually charged in 2016 after another complainant came forward in 2014. He admitted four counts of indecent assault on a man aged 16 or over and one count of indecent assault on a boy aged under 14 years.
In court, one victim said he was told to stay quiet when he told council bosses what was happening.
Richard Rowe, who waived his right to anonymity, said: "They asked for specifics and I gave them as much details as I could bring myself to voice. But they knew, they knew exactly."
After Friday's court hearing, the council apologised and said it 'accepted responsibility and would never defend the indefensible'.
But the authority may be forced to pay compensation to Dodds' victims if it loses a civil case later this month.
The council said it would not comment further as a result of the upcoming hearing, which will take place at Sheffield County Court.
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