French investigators have released a chauffeur for Kim Kardashian West and two other people in their probe into the robbery of more than $10 million worth of jewelry from the star's Paris apartment in October. The driver's brother and 13 others remained in custody Wednesday after a round of arrests this week, according to the Paris prosecutor's office. Authorities are focusing on the possibility that the robbery was an inside job. Officials say brothers Michael Madar, 40, and Gary Madar, 27, worked for the same car service company and were among those arrested Monday. One of them is believed to have driven Kardashian the night of the robbery. Authorities are focusing on the possibility that the robbery was an inside job. French officials did not name the three people they freed. The suspects arrested Monday ranged in age from 23 to 72 and included several people known for prior robberies and other crimes, according to a police document seen by The Associated Press. A French investigating judge may travel to the United States to speak with Kardashian West. The jewels have not been recovered. In neighboring Belgium, the Antwerp prosecutor's office would not comment Wednesday on reports that the stolen goods might have been smuggled to Antwerp, a major jewel trading center. Thieves are believed to have forced their way into the private apartment where Kardashian West was staying during Paris Fashion Week, tied her up and stole the jewelry. Kardashian West has not commented publicly since Monday's arrests.