The board of the Public Investment Corporation (PIC) has written to Finance Minister Tito Mboweni asking to be relieved of its duties, citing various recent events that have "destabilised the institution".
In a letter signed by the board's nine members, including chairperson Mondli Gungubele, who is the deputy finance minister, the members say there have been "various allegations against at least four directors for now".
"There is clearly a concerted effort to discredit the board of directors to an extent that there cannot be any credibility to the work that is executed in fulfilling its fiduciary responsibilities," read the letter.
"It is for these reasons that we now write to humbly request the honourable minister to release us as directors of the PIC."
The PIC said the decision was taken in a meeting held today.
The letter further stated that the board members were aware that the decision will "have repercussions on regulatory and legislative compliance requirements" of what is known as Africa's largest asset manager.
Although the letter did not make reference to any specific allegations, however, the board of the institution which manages R2.08trn in government pension assets has been caught up in various allegations of misconduct and corruption which threatened its credibility.
"These events have been unbearable to us as individuals and have undoubtedly had a negative impact on our professional integrity," they said.
A Commission of Inquiry which has been appointed to probe allegations of impropriety in the corporation this week heard startling evidence of divisions among the board, including allegations of corruption against directors by an unknown whistleblower via email.
It has also emerged that the board was divided over the handling of corruption allegations against former chief executive Dan Matjila who resigned in November.
The directors said they were willing to remain in their positions until a new board is appointed, which they hoped "will be done on an urgent basis".