Many South African trophy hunting firms fail to meet industry regulations in a country hard-hit by poaching, the environment ministry said on Wednesday after a series of raids.

Investigators found that tannery and taxidermy industries failed to comply with the Threatened Or Protected Species Regulations (TOPS) regulations and national standards regarding the marking of trophies from rhinos and their horns, as well as other game.

Authorities said the blitz was meant to enforce stricter control over the movement of rhino horns in the wake of increased poaching, with 339 rhinos killed since the beginning of the year.

"From a biodiversity perspective, the most frequent issues of non-compliance related to the absence of hunting registers and the absence of TOPS permits," the department said in a statement.

According to environmental regulations, tannery operators were expected to obtain licences to transport rhino horns from trophy hunts to taxidermists for processing and export.

In return, the taxidermies were required to keep a register detailing the receipt of rhino horns, their weight and the numbers of micro-chips inserted inside the horns.

Poor waste management processes and pollution were also cited.

South Africa allows a limited number of trophy hunts every year, but some traffickers have exploited the hunts to export horns to Asia, where they are then used in the lucrative traditional medicine market.