Media watchdog Reporters Without Borders on Thursday called for the release from Afghan custody of the local assistant and driver of formerly kidnapped Canadian journalist Mellissa Fung.

The 35-year-old Canadian Broadcasting Corporation (CBC) journalist was freed on November 8 in a prisoner swap arranged by Afghan intelligence for the family of her abductors, after being held hostage for four weeks in a hole in Afghanistan.

Her "fixer" and driver, brothers Shokoor Feroz and Qaem Feroz, however, remain in the custody of the Afghan intelligence agency, the National Directorate of Security, after being picked up hours after her abduction.

If proof of their involvement in the kidnapping exists, it should be presented to a judge," said Reporters Without Borders in a statement. "But it seems more and more evident that their prolonged detention is a mistake.

Fung herself said in a CBC interview the two brothers were not involved in her abduction, noting they had worked for three years with the CBC.She said her captors were a criminal family who made a living kidnapping foreigners and demanding ransoms, and that she was randomly targeted.