More than 10,600 artifacts dating from Neolithic times that were removed illegally by Nazi archaeologists during World War II have been returned to Greece from the German Pfahlbaumuseum, the state-run Athens-Macedonia News Agency (AMNA) reported on Tuesday.

The items were officially handed back to Greece during a low-key ceremony attended by Greek and German officials in Athens, including Culture Minister Constantinos Tasoulas, German Ambassador to Athens Wolfgang Dold and Pfahlbaumuseum Director Gunter Schoebel.

The return of the artifacts, most of which were excavated in the Thessaly region in 1941 during an operation organized by Hitler's chief ideologist Alfred Rosenberg, arose from a doctoral thesis by Angelica Douzougli, an honorary ephor of antiquities. She located the artifacts in the 1970s over the course of research conducted in Germany and has since spearheaded the campaign for their repatriation.

The objects include pot shards, stone tools, obsidian and flint blades and bone material that were dug up in an effort by the Nazis to claim that northern people, ancestors of the Greeks, had an established presence in Europe from prehistoric times.

"Unfortunately, the most important material, eight boxes that remained in Volos in 1941, is now lost," Schoebel said, according to the AMNA.

The artifacts will be housed temporarily at the National Archaeological Museum, which also has material returned by Germany in the 50s.

The study of the material will be augmented by photographs from the 40s showing bygone lake communities in Thessaly that resemble those of the the Pfahlbaumuseum on Lake Constantia.