About five years ago, executives at Compagnie Financière Richemont, the Swiss luxury group that owns 11 high-end watch brands including Cartier, IWC Schaffhausen, Jaeger-LeCoultre and Vacheron Constantin, began to notice a worrisome trend.

“Watch and jewelry theft was increasing quite alarmingly,” Frank Vivier, Richemont’s chief transformation officer, said on a recent video call. “People in broad daylight in well-heeled districts started to report they had watches ripped off.” For example, news reports said more than 6,100 watches were reported as stolen to Metropolitan Police in London last year.

Mr. Vivier attributed the spike in watch thefts around the world to the proliferation of resale websites, which he said have made it easier to fence stolen merchandise.

In March, at the Watches and Wonders fair in Geneva, Richemont announced a free online platform called Enquirus, designed to address the problem by encouraging watch and jewelry owners to register their pieces on its app or website, using brand names and serial numbers. They would then be able to report them online as lost or stolen, should the items go missing. Anyone considering a purchase who suspects that the watch or jewel has been stolen could then check the database.

The company hopes the platform will reduce the incentive for criminals to steal the items in the first place, as identifying lost and stolen items makes resale much more challenging. “We decided we needed to make it difficult for criminals,” Mr. Vivier said.

Enquirus was conceived two years ago and tested until December, when the current platform was released. Mr. Vivier said it now has more than 6,000 accounts across more than 100 countries, and nearly 30,000 pieces have been registered as lost or stolen. Richemont said all its brands have been promoting the site, and it has informed police and insurance companies, too.

“It is one place for key partners, including law enforcement agencies, insurance companies, the pre-owned market, collectors and individuals to use and quickly search free of charge,” Mr. Vivier wrote in a follow-up email. “It is open to all luxury brands, and currently has more than 190 luxury watch brands and several top jewelry brands already pre-loaded.”

Enquirus is not the first registry of stolen luxury goods. In the United States, the F.B.I.’s National Crime Information Center and the independent LeadsOnline are widely used by members of law enforcement, while the Watch Register in London primarily serves dealers trying to determine if a watch had been stolen.

Enquirus is, however, the first such service available free to consumers, backed by a deep-pocketed organization such as Richemont, said John Kennedy, president of the New York-based Jewelers’ Security Alliance, a nonprofit organization committed to safeguarding the industry from crime.

Mr. Kennedy said the increase in watch theft was part of an overall surge in crime affecting the entire industry. “We had the most crimes against jewelers in the U.S. last year than we ever had,” he said. “It was a more than 30 percent increase over any previous year.

“It dipped way down during Covid when things were closed and travel was restricted,” Mr. Kennedy added. “It was down in ’20 and ’21, and in ’22 it really exploded. We’re seeing it continue today.”

Mr. Vivier said Richemont was intent on creating “a level of emotional reassurance” for prospective watch buyers who may have been deterred by recent media reports of brazen robberies in cities like London and Los Angeles.

Whether Enquirus will help curb theft will depend on how many people use it, Mr. Kennedy said. “To have a database work, you have to have enough critical mass of people entering data on stolen property and enough critical mass of the public knowing about it to make the inquiries,” he said. “They’ve got to know it exists, and that’s a major effort. But Richemont has the resources.”

Recovering stolen merchandise, however, “is a whole other can of worms,” Mr. Kennedy said. “Say I’m a cop with a victim in L.A. and I get this notice that the stolen watch has turned up in Geneva. What the heck am I supposed to do about that?”