The trial of a Frenchman accused of making millions selling fake luxury watches is putting the spotlight on an elaborate commerce of lucrative replicas spanning the globe.

Nicknamed "the prince of fake," Julien V. has freely admitted to running a network of fake watch sales into France from Thailand between 2019 and 2022, before being arrested.

He told investigators that contractors in China produced up to 10 watches per day for him -- most of them fakes of luxury Swiss brand Rolex -- resulting in total sales of 12,000 watches for a turnover of three million euros ($3.3 million).

However a watch expert quoted in the Nice-Matin newspaper, Michel Vittini, said he believed Julien V. sold "at least 50,000" fake Rolexes.

Some of them appear to have been virtually indistinguishable from the real thing, with Julien V. claiming that he could "make it completely real, or completely fake" depending on "what makes the customer happy".

A credible China-made Rolex replica was priced at 500 euros, rising to 1,300 euros if it also had the double of a genuine serial number engraved, he said.

For 6,500 euros the watch had an original automatic mechanism, and a custom-made timepiece made of entirely genuine parts could go up to 60,000 euros.

Real Rolexes cost from around 5,000 euros to upwards of 70,000 euros, and keep or increase their value in the second-hand market.

The high-quality fakes attracted the attention of Swiss watchmakers who hired private investigators, according to French media.

Investigators closed in on Julien V. after arresting some of his online resellers.

On trial since last week, he has taken charge of his own defence at the trial where he faces an army of lawyers for half a dozen of Swiss luxury watchmakers who have brought a civil case against him.

Julien V., born in the French Riviera city of Nice in 1994 and a former pizza delivery man, said that he was a millionaire by the time he was 25, had 4 million euros stashed away in crypto-currency bitcoin and owned a Lamborghini as well as several properties in Thailand.

Accepting orders via WhatsApp, he would ship the watches first to Germany to avoid attracting the attention of French customs, and then into France through the open border between both countries.

One of his co-defendants, reseller Florian R., said that he would buy fake Rolexes for 200 euros and sell them on for 400.

Asked by the presiding judge why he didn't charge more, Florian R. said: "These are fakes, I don't cheat people."

The verdict in the trial is due on March 20.