Three people were sacked and one was prosecuted in court as Bristol City Council investigated 50 reports of fraud by its employees.
Two staff members were sacked for theft and a third was dismissed for holding two overlapping jobs and being suspected of falsifying timesheets.
The cases were set out in the city council’s annual fraud report.
It revealed that reports of fraud by council staff had doubled in the last three years.
Bristol City Council’s counter-fraud and investigation team’s investigations saved the city over £4.2m in 2019/20, according to the report.
The authority prosecuted a carer who continued to claim payments for looking after someone after the person in their care had died.
The carer admitted the offence in court and was sentenced to do unpaid work and to repay the money they fraudulently obtained.
An officer from the counter-fraud team told members of a council committee that some of the investigations completed last year were sparked by whistleblowers from within the council.
Green councillor Clive Stevens said: “I just think it’s really important we keep hammering this home, that Bristol City Council is an open employer and if you think something dodgy’s going on, you are safe [to report it].”