Two men could face charges Wednesday over the spectacular theft of priceless jewels from the Louvre museum, as a Paris prosecutor promised an update in the case.

Dozens of detectives have been on the trail of four thieves who used a cherry-picker truck and cutting gear to break into a first-floor gallery at the world-renowned museum on the morning of October 19, then fled with jewellery estimated to be worth more than $102 million.

But few details have emerged so far about how investigators have managed to track down the culprits, some of whom wore balaclavas and high-visibility vests.

Two men were arrested on Saturday in connection with the heist in the heart of the French capital earlier this month, with their time in custody due to expire on Wednesday evening, meaning they could face charges in the case.

Laure Beccuau was expected to hold a press conference at 17:00 local time (1600 GMT), her office said.

A source close to the case this weekend said the men in their thirties were known to the police for committing thefts.

They hailed from Seine-Saint-Denis, a region just outside Paris, and one was arrested as he was about to board a plane for Algeria, the source said, requesting anonymity because they were not authorised to speak to the press.

After media reports of the detentions, Beccuau said authorities had "carried out arrests on Saturday evening", and confirmed that "one of the men arrested was about to leave the country" from the capital's Charles de Gaulle airport.

- Halloween trend -

Last week, Beccuau told local media that detectives were investigating "150 DNA samples, fingerprints and other traces".

She said public and private security cameras had allowed detectives to track the thieves "in Paris and in surrounding regions".

The thieves dropped a diamond- and emerald-studded crown as they escaped, and police found a yellow vest several minutes away by scooter that they believe belonged to one of the culprits.

The burglars made off with eight other items of jewellery.

Among them are an emerald-and-diamond necklace that Napoleon I gave his wife, Empress Marie-Louise, and a diadem that once belonged to the Empress Eugenie, which is dotted with nearly 2,000 diamonds.

The brazen theft made headlines across the world, and has inspired a new trend in Halloween costumes involving black balaclavas, tiaras and bright yellow vests.

It has also sparked a debate in France about the security of cultural institutions.

Less than 24 hours after the high-profile break-in, a museum in eastern France reported the theft of gold and silver coins after finding a smashed display case.

The Louvre's director Laurence des Cars last week admitted that security cameras did not adequately cover the thieves' point of entry.

But she defended a multi-million dollar plan to increase security at the museum.