Corruption Watch has identified "sextortion" as one of the most alarming forms of wrongdoing at schools. This involves pupils having to use sex to persuade teachers to give them better marks for their exams.
The corruption watchdog's Melusi Ncala said although many complaints relating to sextortion have not been laid, it managed to get more information from learners during its awareness campaigns.
"...Especially when we speak to learners in our engagement, learners will make it known that this teacher and that teacher had asked me [them] for sexual favours in return for better marks," said Melusi Ncaba, Corruption Watch researcher.
In its latest report released on Thursday, the highest number of corruption cases involved schools where principals or school governing body members were implicated in embezzlement. Officials were believed to be using school funds to renovate their private homes and rent luxury vehicles.
The study looked at organisations that had been riddled with mismanagement and fraud. The second highest number of corruption cases were in the SA Police Service, followed by municipal departments, road traffic and licensing centres.
Principals in government schools were found to be coercing parents to pay school fees, which they keep for their personal use.
Often, when parents or guardians refuse to pay, school management abuses its power and sometimes threatens to withhold progress reports, the report states.
The study also exposes nepotism and irregularities in school recruitment processes. Principals allegedly employ preferred candidates for positions, many of them friends and family members. In some cases, staff members are given increases without following the appropriate procedures.
Corruption Watch said it had been working with government since 2013 to curb corruption at schools, prompting whistleblowers to report incidents.
Corruption in schools will not be solved overnight, said Ncala. "It's a work in progress."
"It is clear from this report that the extent of corruption in South Africa remains alarmingly high. However, the determination of people to expose corruption highlights the important role played by whistleblowers in holding corrupt individuals to account." Corruption Watch
The report records Gauteng as the province wth the most corruption at 37.3%, while the lowest is the Northern Cape with less than 2% of the overall cases reported.
The three metropolitan municipalities yielding the largest volume of corruption reports are those of Johannesburg, Tshwane and Cape Town. Of these three, only Tshwane has shown a decrease since last year.
The types of corruption most commonly experienced are bribery, embezzlement of funds, irregularities in procurement and irregularities in employment. Bribery, however, remains the most prevalent form of abuse of power, at least in relation to complaints received from the public.
"It is clear from this report that the extent of corruption in South Africa remains alarmingly high. However, the determination of people to expose corruption highlights the important role played by whistleblowers in holding corrupt individuals to account," the organisation said in a statement.