Swiss officials have arrested two more people in the case of engineer Urs Tinner accused of helping Libya's now abandoned effort to build a nuclear bomb, a spokesman said Saturday.
Hansjuerg Mark Wiedmer, spokesman for the Federal Prosecutor's Office, declined to identify the two, or say whether they were related to Tinner. Wiedmer said the two people have been in investigative detention since Monday.
Tinner, who was arrested last year in Germany, was extradited to Switzerland in May. Swiss authorities have been investigating him on suspicion of violating export laws on controlled goods and war materials.
German authorities said Tinner is suspected of being part of an international network of nuclear smugglers under ringleader Abdul Qadeer Khan, the creator of Pakistan's atomic weapons program.
Tinner is alleged to have overseen machine work in Malaysia on gas centrifuge parts that were intercepted by Western intelligence in October 2003 on a ship bound for Libya.
Gas centrifuges are needed to enrich uranium for use in nuclear weapons.
Tinner's name first surfaced last year when Malaysian police said his father, Friedrich Tinner, was an associate of Khan. Tinner's family confirmed the father had known Khan since the 1970s, but said he was uninvolved in the transactions.
Urs Tinner's younger brother, Marco, reportedly owns a Swiss-based company that sold equipment to the Malaysian firm that manufactured the parts sent to Libya, AP reported.