Four thousand former miners suffering from lung disease have launched South Africa's biggest ever class action lawsuit against some of the world's leading gold producers.

Al Jazeera reports the miners have filed affidavits in the High Court of South Africa against Anglogold Ashanti (NYSE:AU), Goldfields (NYSE:GFI) and Harmony Gold (NYSE:HMY).

The plaintiffs claim they contracted severe occupational lung ailments, such as tuberculosis and silicosis, while working  in underground mines, and are demanding millions of US dollars in compensation from the mining companies.

Little research has been conducted into the incidence of lung disease amongst South African miners, and the few studies undertaken by mining companies so far have focused largely upon white workers.

A 2011 article by Jill Murray and Tony Davies from the School of Public Health at the University of Witwatersrand claims that the highest rates of TB in the world are to be found amongst South Africa miners, with around 160,000 sufferers in total.

Despite the high prevalence of tuberculosis and similar lung ailments Richard Spoor, a human rights attorney who has worked extensively with the miners, claims that fewer than 5% of eligible former workers receive compensation.

Spoors says that even those miners fortunate enough to obtain compensation typically only see trivial sums of around $4,100, as currently mandated by South Africa's Occupational Diseases in Mines and Works Act (ODMWA).

This nonetheless remains an improvement compared to practices in just the recent past. As recently as 2011 the ODMWA contained a clause which made mining companies immune to legal action for lung diseases contracted by either former or current employees.