Sex workers were relieved when they heard that their work in South Africa was about to be decriminalised.

But their joy was short-lived.

Deputy Justice Minister John Jeffrey has announced that with the impending decriminalisation of sex work, existing laws, including residence for foreign nationals, and municipal by-laws, will still need to be respected.

This was a huge blow to the ladies of the night, with the majority being foreign nationals and mostly without legal papers to be in the country.

Most sex workers are vulnerable to both criminals and authorities. Some are sometimes attacked by clients or their handlers and can't report these crimes as their trade is illegal.

NGOs have been campaigning for the decriminalisation of sex work.

In Plastic View, an informal settlement in Tshwane, a group of sex workers said NGOs that usually assist them raised their hopes for nothing.

They said while they were still celebrating, they heard that they would still need to be documented.

"Sometimes clients would refuse to pay us and would tell us to go to the police station to report them. Squatter camp leaders make us pay protection fees and it is hard to get help. We thought those things were behind us," said a sex worker.

She said getting documentation is hard.

"There are so many bribes to pay to officials in our country and here in South Africa. Sometimes our applications are declined and we have no choice but to come here illegally," she said.

Jeffrey said existing laws such as municipal by-laws on loitering would be the municipalities' responsibility.

"So existing laws would effectively apply. When it comes to the issue of foreign migrants selling sex, they will not be able to sell sex unless they have a work permit or if they have the ability and the right to work," Jeffrey said.