They include her chauffeur in Paris, Michael Madar. The three were among 17 people arrested in co-ordinated raids across France on Monday.
The driver's brother is still being questioned by police, reports say.
Kardashian West was held at gunpoint and tied up by the robbers while staying at a hotel in Paris in October.
She was targeted at the exclusive flat near Place de la Madeleine while her bodyguard looked after her sister at a nightclub.
The gang stole €9m (£8m; $9.5m) of jewellery, including a diamond ring valued at around €4m.
The two witnesses to the robbery - Kardashian West herself as well the night-watchman - apparently both told police that their aggressors were men "of a certain age". CCTV footage on the street outside also provided crucial evidence.
"We would expect the people who carried out a job like this to be criminals with a certain degree of experience. They would need the connections to be able to dispose of the jewels once they had got their hands on them," one police source told the BBC.
More from Hugh - Did old-timers target Kardashian West jewels?
Throughout the inquiry, police have been investigating whether the gang was tipped off that Kardashian West's bodyguard was not at the hotel residence at the time of the robbery.
Among those arrested on Monday were several figures in their 60s and one in his 70s. The raids took place mainly in the Paris region and at Rouen in the north. An Algerian, identified as 72-year-old Pierre B, was detained at Grasse on the French Riviera.
Although there has been no trace yet of Kardashian West's missing jewellery, police did recover an estimated €300,000 during Monday's raids.(BBC)