Opposition parties have accused the ANC of seeking to use clause 18 of the draft Protection of Information Bill to force journalists to betray sources who hand them classified information to the authorities.
The clause obliges anybody who comes into possession of a classified document to hand it to the police or the intelligence services to avoid prosecution.
Democratic Alliance MP David Maynier asked the committee drafting the bill: "Could it be explained to me what the purpose is of handing the document to the police? Is the danger not that the police could try to determine who had leaked that document to the journalist?"
Luwellyn Landers, who was leading the ANC's arguments on the ad hoc committee drafting the bill, responded: "There is nothing wrong in that."
He added: "Mr Maynier incidentally reveals his whole approach to the law. He finds leaking to be a virtue."
Maynier said his position was "a democratic one" and that the ANC's was not. He added that it was unthinkable that journalists who were handed classified information would rush to a police station to get rid of it.
"It will never happen in a million years, ever. This is madness."
The issue had cropped up repeatedly in recent deliberations on the bill. The ruling party had insisted the clause would stay and rejected opposition proposals for exemptions from prosecution for possession of state secrets.
According to the latest draft, the only exception is where possession is authorised by another law.
The DA had argued the new law should explicitly rule out prosecution where the information was wrongfully classified or concealed wrongdoing.
The issue tied up with that of protection for whistleblowers, which activists and academics said remained lacking in the bill and could determine whether it passed constitutional muster.
Dennis Dlomo, the special adviser to State Security Minister Siyabonga Cwele, said on the sidelines of deliberations that since the latest draft did not criminalise possession per se, provided the police were alerted, the recipient could then, without fear, approach the minister with a request to declassify it.
In this regard, the clause no longer risked creating what constitutional law expert Pierre de Vos called "an Orwellian situation", where one could not ask authorities to declassify a document, because admitting that one had insight into it could land one in jail.
But African Christian Democratic Party MP Steve Swart said in the absence of a public interest defence to protect journalists and whistleblowers, going to court would in reality be "the only route" for somebody who uncovered classified information that concealed corruption.