• Samples sold from £4 each to help gain disability grants • Scam growing as sufferers compete to sell stolen clinic bottles

South Africans in an impoverished township are profiting from an illegal trade in a precious new currency ‑ saliva.

Tuberculosis sufferers in Khayelitsha, Cape Town, were found to be selling samples of their sputum to healthy people to pass off as their own in a scam to gain medical grants.

An investigation by the West Cape News identified people with TB charging R50-100 (£4.10-£8.20) for saliva samples contained in bottles stolen from health clinics.

The paper said that buyers of the samples were then able to get a card from a clinic indicating they have TB and use this to fraudulently obtain a temporary disability grant of R1,010 per month from the department of social development.

A 54-year-old man told a reporter that he makes an average of R500 per month from selling his saliva to people seeking to trick their way on to the benefits system. But he said business was "not good" because so many people were infected with TB in the township that he had a lot of competition.

John Heinrich, chief executive of the SA National Tuberculosis Association, said: "It is definitely happening. People are trying to get a grant by pretending to be TB positive. Instead of handing their own sputum in, they buy it from people who have TB-positive sputum."

He added: "They go to the clinics and get treated as TB patients. People are supposed to produce their sputum under supervision, but I'm sure when the clinics get busy, that doesn't happen."

South Africa has one of the highest TB rates in the world with around half a million new cases each year, resulting in 78,000 related deaths. Poverty, malnutrition, HIV and cramped conditions in townships such as Khayelitsha, one of the biggest in the country, help the infectious disease to thrive.

Heinrich added: "There is so much unemployment, especially in that area of the Western Cape, that if there's a chance to make money, people will jump at it. The authorities should insist that samples are handed in to clinics under supervision."

The West Cape News journalist went to a clinic in the township and was given two bottles by a health worker, but was not asked to cough up the sputum in the worker's presence, making it easy to swap the bottles.

Fidel Hadebe, a spokesman for the national health department, condemned the trade as illegal and "based on greed". He said: "This is wrong and cannot be allowed. People have to be tested by professional workers."