Hosken said after the close of trade on Wednesday it had suspended executive chairperson Marcel Golding pending an enquiry into allegations of "gross misconduct", adding the charges were "of a very serious nature warranting disciplinary action".
However, it said in a regulatory filing that the allegations were "unlikely to adversely affect the operations of the company, or materially affect its financial performance".
Hosken has stakes in several large South African firms, including hotel and gaming group Tsogo Sun Holdings [JSE:TSH]. Golding is Hosken's second-largest shareholder with around 7% of the company, according to Thomson Reuters data.
Golding, who could not be immediately reached for comment, has launched proceedings to stay the disciplinary enquiry, the company said.
HCI, which owns broadcaster e.tv, said in a statement on Wednesday: "HCI regrets to announce its decision to suspend the services of its executive chairman, Marcel Golding, as an employee pending a disciplinary enquiry into certain allegations of gross misconduct by him."
A special sub-committee mandated by the HCI board, comprising its lead independent non-executive director and the chairmen of HCI’s audit committee and social and ethics sub-committees, deliberated on the matter.
"Disciplinary proceedings have been instituted and the process is scheduled to proceed on Monday 27 October 2014," the company said.
"In the interim however, Mr Golding, has responded to the process by launching proceedings to uplift his suspension and to stay the disciplinary inquiry and to seek other relief."
While HCI respected the right of its employees to take whatever legal steps they deemed appropriate in their own defence, HCI would act to protect its interests.
"HCI intends opposing the said application," it said.
HCI has stakes in businesses including gaming and leisure, media and broadcasting, transport, energy, and property.
Shares of HCI fell as much as 6% after the firm suspended its executive chair.