PARIS (Reuters) - French police raced against detention-time limits on Thursday to glean information from people arrested over the gunpoint hold-up of Kim Kardashian, among them underworld figures said to be known by nicknames worthy of Hollywood hoodlums.

FILE PHOTO: Kim Kardashian West participates in a television interview as she arrives for the 20th Annual Webby Awards in Manhattan, New York, U.S., May 16, 2016. REUTERS/Mike Segar/File Photo

Four more of the 17 taken into custody on Monday were freed, taking the number in police hands down to 10 a one day before the deadline by which they should, in normal circumstances, be indicted or released.

Thieves wearing balaclavas and jackets marked ‘police’ burst into the luxury property where reality TV star Kardashian, who is married to U.S. rapper Kanye West, was sleeping in the early hours of Oct. 3.

They tied her up at gunpoint before making off on bicycles with her engagement ring and other jewels worth 9 million euros ($9.5 million), police officials and judicial sources said at the time.

Among those kept in custody on Thursday is a 72-year-old arrested in a village in the hills behind the southern Riviera coast, according to judicial sources, as well as the brother of a man hired to drive Kardashian around during her Paris stays.

The driver himself was among three released on Wednesday.

Earlier this week, police and judicial sources said the 17 rounded up by police in the Paris region, Rouen and near the southern hill town of Grasse included known underworld figures.

The Le Parisien newspaper said in a report on Wednesday the arrested included one known for high-profile motorway robberies, and known in the underworld by a French-language nickname of Nez Rape, pronounced Nay Rappay and which roughly translates into English as Scrape-Nose.

Another netted along with his two sons in a police raid at a house on the eastern edge of Paris goes by the nickname of Omar le Vieux, or Old Omar, the newspaper said.

Standard French procedure when people are taken into custody is that they must either be released 96 hours later or formally placed under judicial investigation on specific counts of suspected crimes.

In the Kardashian case, that gives police until Friday morning to decide whether to release those who remain in custody or decide they have enough information to justify formal investigation.