01/14/2013 09:30 am ET Updated Dec 06, 2017

Diego Rivera Painting Found Behind Office Door Is Worth Up To $1 Million, Says Antiques Roadshow (VIDEO)

Normally we consider the artwork adorning office walls a step above dentist waiting room art. But the painting titled "El Albanil," which hung behind the office door of Texan Rue Ferguson, is a glaring exception.

The unassuming piece, bought by Ferguson's great grandparents in 1920, is actually a masterpiece by Mexican muralist Diego Rivera, as Antiques Road Show revealed last week. The painting, made when Rivera was only 18 years old, is worth between $800,000 and $1 million, but it lived in obscurity in Ferguson's home office for years.

According to the Corpus Christi Caller, Ferguson's great-grandparents originally purchased the work in Mexico and passed it on to his parents, who thought it was a fake. They then kept the work in storage, unaware of its true value. While any Rivera work would be worth a hefty sum, this painting holds particular importance because it shows a young artist of note still developing his craft. Ferguson realized the weightiness of the piece and decided the work likely "needs to be in a museum where everybody can look at it," as he explained during his PBS appearance.

See the great reveal below and prepare to be jealous.

Watch Interview: 1904 Diego Rivera "El Albañil" Oil Painting on PBS. See more from Antiques Roadshow.

See other dramatic art finds in the slideshow below:

The Most Dramatic Art Finds Of 2012