A group claiming to be former agents of Israel's Mossad threatened to unleash a devastating cyber attack on South Africa unless its government cracked down on the growing campaign to boycott Israel, according to intelligence documents leaked to Al Jazeera's Investigative Unit.

According to the reports, then-Finance Minister Pravin Gordhan received a note from "unknown sources" on June 28, 2012, threatening a cyber attack "against South Africa's banking and financial sectors." The hand-delivered letter gave the government just 30 days to achieve the "discontinuation of the Boycott Divestment and Sanctions (BDS) campaign and the removal and prosecution of some unidentified individuals linked to BDS".

South Africa's ruling African National Congress has historically aligned itself with the Palestinian national struggle, and the BDS campaign there involves some high profile anti-apartheid struggle figures such as Nelson Mandela's close friend and fellow Robben Island prisoner Ahmed Kathrada.

THE SPY CABLES
A leak of hundreds of secret intelligence papers from agencies all over the world, offering a glimpse into the murky world of espionage.
Al Jazeera's Investigative Unit is publishing a selection of the documents and the stories contained within them. 

Stuxnet and Flame

According to the secret State Security Agency (SSA) briefing from September 2012, the authors of the letter received by Gordhan claimed to be former Israeli secret service spies "with access to various technologies and resources of the Mossad's Electronic assault and defence division".

They also claimed to have helped develop the Stuxnet and Flame viruses, which are believed to have originated in Israel and targeted Iran and other middle-eastern countries.

Stuxnet reportedly crippled one-fifth of Iran's uranium centrifuges in 2010, when the malware was inserted into the computer system at Iran's Bushehr nuclear plant.

South African intelligence investigated the threat, according to the cable, although there is no evidence that the threatened attack occurred or that the government yielded to the mysterious letter's demands.

The SSA did warn that the growing initiatives in South African civil society to challenge Israeli policies could "significantly increase polarization between the Jewish community and pro-Palestinian support groups".

South Africa and Palestine

BDS is a global campaign launched in 2005 in response to Palestinian civil society calls for international sanctions against Israel, and enjoys widespread support in South Africa. The ANC's historical support for the Palestine Liberation Organisation mirrored a close collaboration between Israel and the old apartheid regime in Pretoria, which allegedly included cooperation on nuclear weapons development.

And the BDS movement reminded many ANC leaders of the role that international sanctions and boycotts had played in weakening white minority rule in South Africa, prompting growing support for the Palestinian cause by South African officials.

Paul Mashatile, the Minister of Arts and Culture considered imposing economic and cultural sanctions on Israel "as part of the worldwide BDS campaign and in reaction to Israel's 'destruction of the Palestine society and denial of basic Palestinian rights," the secret document notes.

According to the secret briefing, the South African spies interpreted the letter handed to Gordhan as evidence of a growing dissatisfaction within the local Jewish community over South Africa's perceived hostility to Israel. The document concluded by warning that Mossad-linked Israeli businesses could increase "offensive espionage activities" in South Africa.