Three Paris officials, speaking on condition of anonymity to discuss the ongoing investigation, confirmed that Kardashian West's driver the night of the robbery and his brother were among 17 people taken into custody Monday.
Michael Madar, 40, and Gary Madar, 27, worked for the same livery company, according to two of the officials. The officials were unsure which brother chauffeured the reality TV star the night she was robbed in a rented apartment in the French capital.
An investigating judge may travel to the United States to speak with Kardashian West, a judicial official said, adding that such a trip would not be imminent. The official was not authorized to speak publicly about the investigation and asked not to be named.
The suspects 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.
Police officials said on Monday that subsequent searches of properties associated with the suspects yielded weapons and 140,000 euros ($147,500) in cash. The judicial official could not immediately confirm a French press report Tuesday that more than double that amount of money had been recovered as the inventory proceeded.
French law requires the suspects to be freed by early Friday if they are not charged by then, according to the judicial official, who did not exclude the possibility that some of those detained could be let go earlier.
The police officials would not elaborate on how they believe the theft was planned. Kardashian West's bodyguard was gone for the night, and the robbers forced their way into the private apartment where she was staying, tied her up and made off with the jewelry.
Earlier this month, Kardashian West broke her silence on the robbery in a teaser for her family's reality show, telling two of her sisters her thoughts at the time: "They're going to shoot me in the back. There's no way out."
A spokeswoman for the reality star said she had no comment after Monday's arrests.
Elaine Ganley in Paris contributed.
Copyright 2018 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.