Disclosing the list of South Africa's national key points will not put the country's security and defence at risk, and ministers had even named some in Parliament, the High Court in Johannesburg heard on Monday.

"If dark forces are intent on launching an attack on South Africa, OR Tambo [International Airport] would be a good place to start whether it is a national key point or not," Steven Budlender for the Right2Know Campaign (R2K) and SA History Archive (SAHA) said.

"Allowing the public to know a place like Parliament is a national key point in no way endangers state security."

R2K and SAHA want the police to reveal the national key points under the Promotion of Access to Information Act (PAIA).

National key points are protected from being photographed or identified as key points, and are understood to include military installations and services or factories which are considered strategic.

Budlender said national key points were being identified "left, right and centre", especially by ministers in Parliament.

He said the government printing works was identified as a national key point by a minister who also gave the exact address.

"That was 18 months ago and there has been no threat to the government printing works," he said.

He said it was "extraordinary" that more than one national key point had been disclosed in Parliament without any action taken or threat detected.

"It shouldn't be assumed that secrecy is in aid of security."

Earlier, Viwe Notshe SC, for the State argued that although the National Key Point Act did not prohibit disclosure, the disclosure would put the country's defence and security at risk.

The court heard there were 200 national key points.

Notshe said the disclosure of places where research was done on clothing would not prejudice the country's security.

He said it would however be a "different story" when it came to a place where research was done on chemical weapons.

Budlender said his clients did not want addresses of the national key points but just want to know which areas were considered to be national key points.

"My clients never sought the addresses... The addresses are not sought; simply the place," he told the court.

"All my clients seek is the list, they are not seeking all the documents relating to the national key points."

Matseleng Lekoane, friend of the court for the Mail&Guardian newspaper, argued that it was important for journalists to know where the national key points were to avoid major infringement to the rights of the media and the public.

"They should know when they are going to be exposed," she said.

"Members of the media are exposed and suffer actual harm."

She said for people to comply with an order they had to know what the requirements of the law were for that order.

R2K said on Sunday that civic organisations had complained that the secrecy surrounding national key points had been used "to undermine" the right to know and to protest in public spaces.

The PAIA sets out a number of grounds for the refusal to grant access to information.

These include defence, security and international relations of South Africa, its economic interests and financial welfare, and protection of commercial information of a third party, such as trade secrets and commercial information.

In May last year the police ministry said the National Key Points Act was being reviewed.

Judge Roland Sutherland reserved judgment on Monday.