As well as Poundland, it owns Benson for Beds, Harveys Furniture and Pep&Co in the UK. Its stock tumbled by as much as 29% in Johannesburg.
The JSE says it's been talking to Steinhoff to find out the exact allegations against the worldwide company after the furniture retailer shares plummeted. That deal alone has cost the chairperson R87.7m ($6.4m).
Steinhoff bought the Willenhall-based chain of discount stores for £610 million past year.
The chief executive's resignation will take effect immediately showing how serious it is.
"The trust between Wiese and Jooste is broken, that is why Jooste is out", Syd Vianello, an independent retail analyst in Johannesburg, said by phone.
Wiese is South Africa's fourth-richest person with a net worth of $4.3 billion, according to the Bloomberg Billionaires Index. He and Jooste, 56, both own properties in the scenic wine country around Cape Town, alongside other notable South African businessmen including Whitey Basson, who ran retailer Shoprite Holdings for 37 years until earlier this year.
Former manufacturing arm of Steinhoff Industrial, KAP's share price fell 14% to R7.45.
Wiese borrowed €1.6 billion ($1.9 billion) to buy additional Steinhoff shares through a family trust in September 2016, pledging €3.2 billion of his existing holding as security to the investment banks that lent the money.
Well, Steinhoff employs around 3000 people as perhaps the biggest foreign investor in Australian retailing. Steinhoff Africa slumped as much as 29% in Johannesburg, while Shoprite plunged as much as 6.3%, the biggest fall in nearly a year.
The dramatic sell-off was triggered by the announcement that chief executive Markus Jooste had resigned and "accounting irregularities requiring further investigation" had been uncovered. The company has transformed itself in the past four years from a mostly African-focused retailer to an acquisitive powerhouse that now owns Mattress Firm in the USA and Poundland in the UK.
It said it would also investigate whether previous financial results need to be corrected.
Steinhoff had denied the allegations when they surfaced again in August. The release of Steinhoff's 2017 results was postponed until the probe is over.
Shares were also down by 66 per cent on the German stock exchange.