German officials are finally speaking out about a hoard of art stolen by the Nazis that were found in a single apartment in Munich. The work ranges from the 16th to 20th centuries, providing unknown works from masters like Pablo Picasso and Henri Matisse.

The 1,400 pieces of work were discovered by tax investigators, officials said on Tuesday, reports the Associated Press. The investigation began back in 2010 and the apartment in an upscale area of Munich was searched in February 2012. But it wasn’t until this week that officials came forward with their discovery.

“Our primary goal is to investigate whether there has been a crime," Reinhard Nemetz, head of the Augsburg state prosecutor's office, told the media in Berlin Tuesday, reports USA Today, in response to criticism that they should have come forward before. It would have been “counterproductive,” he explained.

He continued, “It is by no means easy to find the rightful owners, particularly when we are talking about over 1,400 paintings.”

The investigation was first reported on by the German magazine Focus and then, officials finally confirmed it. The man who owned the apartment was identified as Cornelius Gurlitt.

“All these paintings and prints are in a very good condition,” Meike Hoffmann of the Berlin Free University said Tuesday, reports The New York Times. She has been hired to examine the art and when asked how much it was all worth, she replied, “Of course it is of a very high value for art historians.”

It is known that many of the pieces were displayed as “degenerate” art by the Nazis. Works by Marc Chagall, Auguste Renoir, Henri de Toulouse-Lautrec, Otto Dix, Picasso and others were in the collection.

However, it is not known where Gurlitt is, authorities said. Siegfried Klöble, of the Munich customs office, confirmed that it took them three days to take all the artwork out of the apartment, but wouldn’t say where they took it for security concerns.