“You’ll never believe how much I paid for this!” my friend says, wrapping up a sky-blue plate in a bundle of old newspapers. “€60! It’s priceless.”

We’re standing in the middle of the antiques market on place du Marché Fourville. A rather breezy Art Deco hall in central Cannes.

The plate – by cubist artist Fernand Léger, no less – is the sort of work that normally travels with its own bodyguard.

My friend, on the other hand, is less valued locally.

He’s what’s known as an “art nose”. He can sniff out a fake – or a masterpiece – at a thousand paces.

I’d arranged to follow him around three of the city’s top art markets and warehouses to test out the legend that Cannes is awash with unrecognised masterpieces. And it had got off to a pretty promising start…

Antiques market, Place du Marché Fourville, Cannes. Every Monday 8am to 6pm.

A deceptively down-at-heel market selling everything from Fifties Gucci flats to crystal fruit bowls and fading water-colours, this is the perfect place to start your city trawl. During our 30-minute visit, we picked up a signed set of lithographs by Picasso, printed to celebrate the completion of the La Guerre et La Paix fresco in Vallauris, for €200 (market price €2000) and a rare – but chipped – 19^th century Japanese ivory sculpture for €150 (market price once restored €1500) virtually identical to one sold at Christie’s last week.

Insider tip: Don’t be fooled by appearances: a chipped statue can sometimes hide a priceless gem. Swot up on high-end auction sites like christies.com. When it comes to books, go for limited editions in short print runs.

Il était une fois… à Cannes, 106 Bd Du Midi, Cannes La Bocca. Daily 9.30am-6pm.

This ranch-like furniture-and-fixtures warehouse opposite the tiny port of Béal on the Bay of Cannes is owned by an upscale carpenter and vintage furniture fan. Fewer masterpiece-spotting opportunities but we snapped up a ceramic stool by currently-undervalued Fifties actor and sculptor Jean Marais for €80.

Insider tip: Artists drop and rise in value, just like stocks and shares. If you’ve got the space, buy now and profit later.

Art Depot, 1635 Chemin de la Plaine, Mougins, Tuesday to Saturday 9.30am-12.30pm, 2.30-7pm. Monday 2.30-7pm.

An upmarket end-of-series furniture and art store run by English- and Italian-speaking duo Stéphanie, daughter of an antiques dealer, and Eric, who have an eye for up-and-coming local artists. We snapped up a monumental canvas by auction-friendly Nice-based painter Jacqueline Gainon for €260.

Insider tip: Today’s unknowns are tomorrow’s Picassos – so go with your gut. The warehouse is too small to fit everything in, so have a word with Stéphanie if you’re on the look-out for something special.