The South African Communist Party (SACP) says the alleged hacking of Solly Mapaila's email account is part of a protracted campaign to tarnish his reputation.
"This is a campaign by rogue units in various sectors to tarnish [Mapaila's] name. It is an attack on democracy and an invasion of his privacy," the party's spokesperson Alex Mashilo said.
On Wednesday, the party tweeted that Mapaila, its first deputy general secretary and an outspoken critic of President Jacob Zuma, fell victim to an email hack by "rogue units" that has rendered his account unusable.
Mashilo said it first emerged that Mapaila's emails and personal cellphone were being bugged after a report published by a website called "Dodgy SA Ministers" in July.
The article, which does not name its author, reported a series of call logs made through Mapaila's cellphone to other members of the party as well as his wife, Moipone Malefane. It called Mapaila the "biggest and dirtiest lobbyist of white monopoly capital", naming him as a director of a company called the Financial Sector Campaign Coalition.
It also published Mapaila's and SACP boss Blade Nzimande's identity numbers.
Mashilo rubbished the article, saying the company is a nonprofit entity established for the promotion of transformation. He said the article was promoted on Google and that the party wrote to the search engine's branches in South Africa to have it taken down.
"You can see this is a concerted effort to attack [Mapaila]. This was their reply to the Gupta Leaks, thinking they could leak their own information," Mashilo said.
Soon after the article was taken down, Mapaila wrote to the Inspector General of Intelligence asking to institute an investigation into the alleged tapping of his cellphone.
"This is a complete violation of my privacy as a citizen...This indicates the intention of putting the SACP operations under an illegal surveillance, and its confidentiality has been completely compromised," Mapaila wrote.
Mashilo said it was only afterwards that Mapaila discovered his emails were also compromised.
"We have been battling with [Mapaila's] emails for some time now. Sometimes they would not go through to him until recently, when he was denied access into it. It was like someone had changed his password. After [Julius Malema] came out saying a similar thing happened to him, we said we could not keep quiet about it," Mashilo said.
He said the party would engage with the State Security Agency and the Inspector-General of Intelligence on the way forward.
But as the run-up to the ANC's national conference in December shifts up a gear, more and more allegations of various dirty-tricks campaigns are coming to the fore.
Economic Freedom Fighters boss Julius Malema announced on Twitter on Tuesday that his email accounts had allegedly been hacked. He believed the state was behind the hack.
In September, Deputy President Cyril Ramaphosa's personal email accounts were allegedly hacked, and the data leaked to media outlets, which reported that the presidential candidate allegedly had affairs with a number of women, some of them students.
Ramaphosa claimed the leak was part of a dirty-tricks campaign to smear his reputation.
Institute for Security Studies senior researcher Johan Burger said it can be assumed that when a country has an intelligence agency, it will have access to technology used to bug cellphones and other devices.
"But there is a legal process that has to be followed, and an order must be obtained from a court before any intelligence or information can be gathered... We know from past experience, [in which] Crime Intelligence has used such technology to access information without authorisation," Burger said.
"When you have continued political interference in these agencies when it comes to the selection of leadership... people in positions of authority are not interested in the lawful use of these technologies and will abuse their capabilities."
He said that until the country arrives at a transparent process in appointing leaders at various institutions like the police and intelligence agencies, we will not have credible usage of intelligence facilities.