The DA has demanded the minutes of all discussions held by the National Coronavirus Command Council (NCCC), including the decision to continue the ban on tobacco products.
The party's interim leader, John Steenhuisen, said the DA had filed an application in terms of the Promotion to Access to Information (PAIA) Act to get access to the records that have so far been described as classified.
He railed against the continuation of the "destructive lockdown" in its current form, which turned South Africans into "subjects of an authoritarian state".
Steenhuisen was speaking on Friday in an online "announcement of national importance".
He said when President Cyril Ramaphosa announced South Africa would be placed under lockdown six weeks ago, it was the correct decision.
It was done to give South Africa time to prepare for its response to the pandemic, the DA leader added.
"Level 4 of the lockdown, as it turns out, is hardly different from Level 5. In fact, in many respects it is more restrictive, not less," Steenhuisen said.
"This wasn't progress towards a more open society and economy at all. It was simply an extension of the hard lockdown - this time with no final deadline in sight."
Steenhuisen spoke of the devastating impact of the pandemic on the economy - negative growth and job losses.
"We are no longer dealing with a Covid-19 crisis. We are dealing with a lockdown crisis. An ANC lockdown crisis to be precise.
"Let me be very clear about this: There is no longer a justification to keep this hard lockdown in place. The government cannot produce this justification."
Steenhuisen said it was crucial everyone knew why the government continued with the lockdown.
"They cannot show us the modelling they use to decide when to ease and when to tighten restrictions. They cannot do this because they don't seem to know for sure themselves."
He complained every decision was shrouded in secrecy and described the NCCC as "a small group of Cabinet ministers who don't answer to Parliament or anyone else".
"When asked for their meeting minutes to clarify why they backtracked on lifting the cigarette ban, this National Command Council refused, claiming this was classified information.
"I don't buy that for a second, and neither should you."
Steenhuisen said the DA had filed a PAIA application to obtain not only the minutes of its discussion, but of other decisions relating to the lockdown.
"If there is a good reason for maintaining the lockdown, based on a scientific modelling of this pandemic, then we need to know what this reason is. We need to see government's modelling.
"If no reason and no modelling can be shared, then we have no choice but to suspect that government is acting irrationally, or deliberately instilling fear to further some other agenda."
He said the DA's approach to the lockdown would entail localised lockdowns based on information, allowing more businesses to open and people to return to their livelihoods, still using precautionary measures like physical distancing, masks and the regular cleansing of hands.
Steenhuisen added true bravery and compassion would be for Ramaphosa to end the lockdown.
He said if not, millions more citizens would start breaking the law in the coming days and weeks.
"If you don't end it, the people of South Africa will take charge and end if for you."