A Mona Lisa-lookalike that could be worth millions is the subject of a new lawsuit filed by a prestigious European family seeking partial ownership of the coveted painting, according to a report.

The “Isleworth Mona Lisa” was discovered in the early 20th century by a collector in an English country house, CNN reported.

The collector, an artist himself, was convinced the painting depicted a younger Lisa del Giocondo — Leonardo da Vinci’s real Mona Lisa muse.

The painting had been stowed away in a Swiss bank vault since 1975, until an international consortium purchased the work in 2008 and began displaying it in galleries across the globe, CNN reported.

In June, when the painting went up at Florence’s Palazzo Bastogi, the anonymous European family came forward to claim 25 percent ownership of the piece.

The unnamed claimants — described by their lawyer only as a “distinguished European family” — allege the painting’s former owner promised the family a 25 percent stake in the work, according to CNN.

A Florence court will weigh the family’s request on Monday to sequester the painting, which would prohibit it from leaving Italy while its ownership is probed.

The “Isleworth Mona Lisa” could net an enormous payout. Long considered a da Vinci fake, the “Salvator Mundi” broke art-sale records when it sold for $450.3 million in November 2017.