A German man and his colleague appeared in court Thursday on charges of violating South Africa's ban against nuclear proliferation, according to news reports.

Gerhard Wisser, 66, is accused of receiving more than $1 million to arrange for a South African firm to manufacture parts for a gas centrifuge used to enrich uranium, according to the reports. Prosecutors say the parts were intended for Libya's atomic weapons program. Wisser had been arrested in Germany in late August and released on bail pending investigation.

The nationality of the other man, identified as Daniel Geiges, 65, was not immediately known.

The men, who were arrested in South Africa on Wednesday, work for Krisch Engineering, a company in Randburg, near Johannesburg. Wisser is managing director of the company. Their lawyers say they have denied any wrongdoing.

Authorities confirmed that the charges are related to the international investigation into the nuclear arms network led by a Pakistani scientist, Abdul Qadeer Khan, who helped Libya and other countries develop weapons programs.

A third man, Johan Andries Muller Meyer, 53, was arrested last week on similar allegations, but prosecutors dropped the charges against him as part of a deal in which he is expected to cooperate with the investigation, officials said Wednesday. Police seized 11 shipping containers from Meyer's company, Trade Fin Engineering, that allegedly contained components used in building gas centrifuges.

The International Atomic Energy Agency is leading an investigation into the Khan network. "We're getting very good cooperation from the South African authorities," said Mark Gwozdecky, a spokesman for the agency.

-- Craig Timberg

and Dafna Linzer