The theft of the artworks, reportedly worth at least €1 million (£890,000) was carried out while the owners were on holiday abroad, said a police official, who spoke on condition of anonymity because of department policy.
The break-in was discovered by a caretaker at the home in La Cadière d'Azur, a medieval Provencal village surrounded by vineyards and olive trees, on Thursday afternoon.
A piece by the artist Amedeo Modigliani, initially believed to be part of the haul, has since been found, police in Toulon said.
The villa's French owner was holidaying in Sweden at the time of the break-in and has now returned home to carry out an inventory of his collection to establish the exact loss.
The discovery of the theft came days after a 19th century drawing by Edgar Degas worth €800,000 (£710,000) was stolen from the Cantini Museum in the city of Marseilles.
The theft of "Les Choristes" ("The Chorus Singers") was discovered when the museum opened on Thursday.
Lent by the Musée d'Orsay in Paris for an exhibition featuring some 20 works by Degas that was due to close on Jan 3, the colourful pastel measures 13 inches by 10.
The painting had been unscrewed from the wall and there was no evidence of a break-in, police said, indicating the thief or thieves knew how to get around the museum's security system.