State capture possibly cost the country more than R500-billion, President Cyril Ramaphosa has told a gathering of international investors.

The president was speaking at the Financial Times Africa Summit in London on Monday. Responding to questions following his delivery of the opening address, Ramaphosa weighed in on efforts to rid the country of corruption and measures to be taken against those implicated – including the Gupta family.

"We have been working on how those who are complicit in the widespread corruption can be brought to book," Ramaphosa assured.

News24 recently reported that South Africa has approached eight countries – including India, Canada, Switzerland, Mauritius and the United Arab Emirates – to have the Guptas extradited to face prosecution for years of State capture.

"Our country was dogged by corruption across the board, in both the public and private sector," Ramaphosa commented.

"A lot of money was syphoned out of state coffers through corrupt means. Some of those [operations] were sophisticated. Some of those included blue chip companies of great world reputation … that is the shocking part," he said.

He said that government, through its various agencies, such as the prosecuting authorities and crime intelligence authorities, was working to bring to book those complicit in corruption.

"I am more confident than I have been in the past that the [National] Prosecuting Authority will be going after those complicit in criminal activity. Whether in the country or outside the country – [we] will follow them up," he said.

Responding to a question on the scale of corruption, Ramaphosa said it was "bigger" than what people may have imagined. Putting a number on it, Ramaphosa said State capture could have easily cost the country more than R500-billion, while others have suggested it could be R1-trillion.

But Ramaphosa gave his assurance that steps have been taken to strengthen institutions that were weakened in the past to enable corruption. He listed the South African Revenue Service and the National Prosecuting Authority as examples of institutions which have been repositioned to act independently.

"We have stemmed the bleeding we are ready to open a new chapter. Those responsible will be brought to book… We will chart a new course of clean governance and avoid corrupt tendencies," he said.