As the investigation into the brazen heist at the Louvre Museum in Paris stretched into its 16th day on Monday, authorities said the whereabouts of the stolen jewels remain a mystery despite four suspects being charged in the case.

Paris public prosecutor Laure Beccuau said in a radio interview on Sunday that three of the suspects so far have been linked to the Louvre robbery through DNA and insisted that detectives have not exhausted all the leads that have poured in since the probe began.

“All leads are being explored,” Beccuau told Franceinfo radio of efforts to recover the jewels.

Beccuau added that the arrests made in the Louvre investigation have “led to new searches and the seizure of new objects that are being examined.”

“We are following leads that, for the moment, have absolutely not been exhausted,” Beccuau said.

Beccuau said one suspect who played an active role in the heist remains at large, while three others have been charged with organized robbery and conspiracy to commit organized robbery.

Where are the missing jewels?

The prosecutor said investigators have not given up on recovering the $102 million in jewels.

“We are examining all aspects of the parallel market,” Beccau said.

But Christopher Marinello, CEO of Art Recovery International, a private company that specializes in locating looted artworks, told ABC News that he fears the jewels might have been dismantled by now.

“As we’ve said from the beginning of this theft, if the jewels are not recovered in the first 48 hours, they are most likely broken up into smaller jewels and gems and sold in the marketplace,” Marinello said.

Asked if there is any way to identify the thousands of individual diamonds, emeralds and sapphires that compose each of the missing eight pieces, Marinello said, “Many of the smaller stones are virtually untraceable to this collection.”

“Only the larger stones could possibly be traced to this but, unfortunately, those are the stones they will have wanted to break up as quickly as possible,” Marinello said.

What’s known about the suspects

Marinello told ABC News that the key to finding the stolen jewels depends a great deal on the interrogation of the suspects.

“I’m talking like Dirty Harry-type interrogation,” Marinello said. “If you just ask them nicely, they’re not going to tell you where they are or who their compatriots are.”

During Sunday’s interview with Franceinfo radio, Beccuau said the suspects do not appear to be international criminal masterminds.

“This is not quite everyday delinquency … but it is a type of delinquency that we do not generally associate with the upper echelons of organized crime,” Beccuau said.

Beccuau said the suspects charged so far appear to be petty criminals and blue-collar workers from northern Paris suburbs.

A 39-year-old taxi driver and a unemployed 34-year-old former garbage collector were the first suspects arrested in the case.

Beccuau said both men are suspected of being the two thieves that used a truck-mounted mechanical cherry picker to get up to the second floor of the Louvre and break into the museum’s Apollo Gallery using power tools.

The Apollo Gallery has remained closed since the heist, according to the Louvre’s website. It is not clear when it will reopen.

Beccuau said investigators have not recovered any evidence “of the existence of complicity” with someone working inside the Louvre.

The 34-year-old suspect was arrested on Oct. 25 at Paris-Charles de Gaulle Airport as he was about to board a flight to Algeria with a one-way ticket, officials said. Beccuau said the suspect’s DNA was recovered from one of the scooters used in the getaway.

Beccuau said the 39-year-old suspect had previously been arrested for aggravated robberies in 2008 and 2014 and his DNA was found on a window at the Louvre.

Beccuau said the two suspects “partially admitted their involvement” in the Louvre heist to investigators, but she did not elaborate.

On Oct. 29, five additional people were arrested during raids in the Seine-Saint-Denis region north of Paris in connection with the Louvre heist. Three of the five people detained were later released without being charged.

But one of the people detained in the Sein-Saint-Denis raids was described as a person of interest due to his DNA being found at the scene of the crime, authorities said.

While the names of the suspects have not been released, authorities announced the arrests on Saturday of a 37-year-old man and his 38-year-old domestic partner, both from Seine-Saint-Denis.

Beccuau said the 37-year-old suspect’s DNA was recovered from the mechanical cherry picker used in the robbery. She also said the suspect’s criminal history shows he has 11 previous convictions, 10 for theft, including one he committed in 2015 with the 39-year-old suspect in custody.

The 37-year-old and his domestic partner, who have children together, were charged with organized robbery and conspiracy to commit organized robbery. The couple have denied involvement in the Louvre heist, Beccuau said.

Beccuau said “at least one person” who was an active participant in the robbery remains at large.