The South African Revenue Service (Sars) led a large-scale government search and seizure operation against several alleged members of coal smuggling syndicates across the country on Thursday, including former Eskom employees.

"The alleged coal-smugglers and their related entities are active and have a presence in Gauteng, Mpumalanga, KwaZulu-Natal, the Free State and Limpopo," the tax authority said in a statement.

"The suspects targeted today include former Eskom employees who facilitated procurement fraud, as well as other individuals involved in the diversion of high-grade coal."

Sars said it established that the suspects had contravened several tax laws, including non-registration for income tax, failure to submit tax returns, under-declaration of income, claiming undue VAT refunds, and making false submissions.

Sars put the loss of revenue to the fiscus by the syndicates at over R500-million.

Coal smuggling syndicates have been a consistent problem for Eskom. Often, trucks transporting coal to power stations are diverted to specific coal yards, and high-quality coal is swapped out for low-grade product, scrap or rocks. When the lower-grade products are used at the station, they cause infrastructure damage, rendering them unable to generate electricity, leading to more loadshedding.  

Sars Commissioner Edward Kieswetter said the raids were a massive breakthrough in ongoing investigations into the syndicates. 

"It is because of such naked greed that the country has experienced unprecedented loadshedding, which harms business, undermines foreign direct investment and leads to job losses - all of which negatively affect revenue collection.

"All law enforcement agencies must continue their aggressive fight against criminality, each according to its mandate. For its part, Sars will continue to pursue taxpayers." 

It was not clear from the statement what exactly was seized. In a response to specific questions from News24, Sars said it had led the operation because it had been investigating tax matters. However, it declined to give further information.

"Sars cannot provide any more details on these investigations, in line with the Tax Administration Act," it said.

At present no one has been arrested. 

The police also did not immediately respond to requests for further details.