Brown’s deadline comes after she told journalists in Parliament on Wednesday that she did not know whether Eskom was lying about its relationship with Trillian, a Gupta- linked company.
The minister was speaking to journalists after she met with the standing committee on public accounts over a separate matter.
Eskom had been given 48 hours since the board meeting on Wednesday to respond to the Trillian report.
After the board meeting, Eskom said it had suspended some of its top officials. Eskom said the board discussed the progress in various investigations and disciplinary processes. It said it would take action against those involved.
“The 'Technical Review' matter will attract a charge against the responsible individuals once the facts have been confirmed. Disciplinary processes against four senior executives are continuing, and the charges have been served to the individuals concerned,” Eskom said in a statement.
It did not name the top officials under suspension.
Brown said she would wait for Eskom’s response on Thursday.
“I have given them 48 hours I think I should give them natural justice,” she said when asked if she would take action against Eskom for lying.
She said she had no idea if Eskom was lying about the Trillian matter, adding that she expected Eskom to give her a full report today.
“I expect them to meet the deadline within 24 hours,” said Brown.
The backtracking of Eskom over payments to Trillian and McKinsey came after months of sticking to the same story in Parliament and outside the institution.
The ANC has called for criminal action against those responsible.
But Natasha Mazzone, of the DA, said they did not buy Brown’s statement that she did not know.
She said the minister must come clean on the relationship with the Guptas.
Mazzone said all those responsible for the latest scandal must be held accountable.
Eskom's chief financial officer Anoj Singh was suspended more than two months ago.
The Organisation Undoing Tax Abuse this week laid criminal charges against Singh over his dealings at Eskom.
It said it wanted Singh and others implicated in wrong- doing to be charged and face the full might of the law.
Eskom has been embroiled in controversy over the past few months, leading to Parliament setting up an inquiry against the power utility.
This week, the portfolio committee on public enterprises was given resources to investigate state capture.
Acting chairperson of the committee, Zukiswa Rantho, said they initially planned to hear their first witnesses on Tuesday, but that would depend on discussions on the scope and evidence to be led.
Three organisations have already told Parliament there was corruption at Eskom and other state-owned entities.