Artist Pablo Picasso was well known for the prolific number of paintings he did, and his catalogue has just grown by one, years after his death. Scientists and historians at the Phillips Collection in Washington have discovered a hidden portrait beneath the luminary artist's, "The Blue Room," one of the Picasso's early masterpieces. 

"When he had an idea, you know, he just had to get it down and realize it," Phillips curator Susan Behrends Frank told the AP, describing how Picasso painted "The Blue Room" over another complete picture. "He could not afford to acquire new canvases every time he had an idea that he wanted to pursue. He worked sometimes on cardboard because canvas was so much more expensive."

The Blue Room was originally painted in 1901 at the beginning of the artists famous, "Blue Period."Art conservations specialists have long suspected there might be something beneath, "The Blue Room." Brushstrokes on the piece clearly didn't match the composition, which depicts a woman bathing.

A conservator noted the odd brushstrokes in a 1954 letter, but it wasn't until the 1990s that an x-ray of the painting first revealed a fuzzy image of something under the picture. In 2008, improved infrared imagery revealed for the a man dressed in a jacket and bow tie with a bearded face resting on his hand with three rings on his fingers. He's dressed in a jacket and bow tie. Curators are continuing with other technology to see if more insights and detail can be gained.

Who the painting is of, still remains a mystery. The notion that it was a self-portrait has already been ruled out. One likely person is art dealer Ambroise Vollard, who hosted Picasso's first show in 1901. But there's no conclusive evidence to support this theory yet.

"It's really one of those moments that really makes what you do special," said Patricia Favero, the conservator at The Phillips Collection who pieced together the best infrared image yet of the man's face. "The second reaction was, 'well, who is it?' We're still working on answering that question."

"Our audiences are hungry for this. It's kind of detective work. It's giving them a doorway of access that I think enriches, maybe adds mystery, while allowing them to be part of a piecing together of a puzzle," she said. "The more we can understand, the greater our appreciation is of its significance in Picasso's life."

Right now the painting is on tour in South Korea until 2015, but curators are already planning a show centered around "The Blue Room" for 2017. It will examine the details of how of the man's portrait was found beneath the painting.