In 2010, Denver’s Museum of Contemporary Art put up a collection of paintings that it wasn’t sure were real or fake.

The style of the paintings is often compared to cubism, with simple geometric shapes and bright colors. The collection looked strikingly similar to the work of Russian Avant-Garde artists like Kazimir Malevich and Alexander Rodchenko, but the identity of the artist, or artists, is still unknown. 

Given the uncertainty over the paintings' origins, the exhibition asked visitors to contemplate what being "authentic" means, according to the art director at the museum.

"We forget that when we say something’s inauthentic, we’re still having an authentic relationship with that painting," Denver’s Museum of Contemporary Art's Adam Lerner said. It’s still something that moves us.”

Lerner wrote a book about the collection called "From Russia With Doubt."