International relations and cooperation department spokesperson Clayson Monyela said on Monday the government had noted with concern the reports published by the UK's Guardian newspaper.
"We do not yet have the full benefit of details reported on, but in principle we would condemn the abuse of privacy and basic human rights particularly if it emanates from those who claim to be democrats," he said.
"We have solid, strong and cordial relations with the United Kingdom and would call on their government to investigate this matter fully with a view to take strong and visible action against any perpetrators."
The newspaper reported that the operation objective was to acquire "retrieved documents, including briefings for South African delegates to G20 and G8 meetings".
It said the British government communications headquarters was trying to find out more about the position of former president Thabo Mbeki's government on global economics and finance.
The Guardian reported that Britain had used "ground-breaking intelligence capabilities" to monitor communications between officials at two meetings in April and September of 2009.
According to the report, British agents repeatedly hacked into foreign diplomats' phones and emails.
Speaking at the G8 summit on Monday, British Prime Minister David Cameron declined to address the issue, the French news agency Agence France-Presse reported.
"We never comment on security or intelligence issues and I am not about to start now," he said.
"I don't make comments on security or intelligence issues. That would be breaking something that no government has previously done." – Sapa