A judge in the United States has ruled law suits accusing five major corporations of helping the South African apartheid government can go ahead, with thousands of claimants set to seek unspecified monetary damages.

Judge Shira Scheindlin dismissed cases against several companies who did business with apartheid rulers, but named five businesses who the complainants claim helped the apartheid government to continue suppressing its people.

The five companies were named as IBM, Ford, General Motors, Daimler and German armament company Rheinmettal Group, while legal action against Fujitsu Ltd, Barclays Bank Plc and UBS AS was rejected.

At the hearing in New York, Judge Scheindlin held that the car manufacturers knew their vehicles were being used by security forces to brutally suppress black South Africans and that software company IBM knew the South African government was using its products to deprive citizens of basic rights.

She rejected IBM’s argument that it was not their place to decide how clients used their products.

Judge Scheindlin said: “That level of willful blindness in the face of crimes in violation of the law of nations cannot defeat an otherwise clear showing of knowledge that the assistance IBM provided would directly and substantially support apartheid.”

Governments in the US, South Africa and UK all supported the companies’ bids to have the cases dismissed, claiming action could damage international relationships and South African economic development.

Thousands of claimants originally brought the case to the federal court in 2002 with allegations against 50 major companies, but they later reduced that number after being asked by the court to supply more details.

South African apartheid ended in 1994 when the African National Congress and Nelson Mandela came to power after he spent 27 years in prison.