Police in South Africa said four individuals including two Mexican nationals and two South Africans have been nabbed by authorities after carrying out the biggest-ever drug bust in a farm located on the border of the country on Saturday.

According to Al Jazeera, the law enforcement agents discovered an industrial scale illicit drugs laboratory that was sitting on a farm in the small town of Groblersdal in the Limpopo province, a province bordering Botswana, Zimbabwe and Mozambique.

The bust which Katlego Mogale, national spokesperson for the Hawks, an elite police unit, said was different due to the involvement of Mexican nationals, uncovered large quantities of chemicals, such as acetone, used in the manufacturing of illicit drugs.

Acetone and other chemicals confiscated during the operation were estimated to be worth two billion rand ($109.5m) in street value, Al Jazeera reported.

“What makes this different from other (seizures) is the involvement of Mexican citizens,” Ms Mogale said. “It means that our task has just become very difficult,” she told the Reuters news agency.

Ms Mogale noted that investigation continued as it was unclear whether the four suspects namely Gonzales Jorge (51), Gutierrez Lopes (43), Simphiwe Khumalo (35) and Frederick Botha (67), were manufacturing to distribute within or outside the country.

According to the United Nations Office on Drugs and Crime, South Africa is one of the largest meth markets in the world and a transit location for illicit drugs.

The four men, which include the owner of the farm, were arraigned in a court in Groblersdal in connection with the case but were not asked to enter a plea. Their next hearing will be on 1 August.