Collector Cornelius Gurlitt's spokesman, Stephan Holzinger, said in a statement Wednesday the complaint against the decision to search Gurlitt's apartment and seize the art was filed last week at a court in Augsburg, where prosecutors handling the case are based.
The works were seized by authorities investigating a tax case in 2012 but the case became public only last November. Officials kept the find secret until it was publicized by a German magazine in early November.
Authorities are checking whether 458 of the pieces were seized by the Nazis, but plan to return works belonging indisputably to Gurlitt. Separately, the collector's representatives say they're in negotiations with six claimants seeking about 40 works.
Gurlitt's representatives argued in their appeal to the Augsburg court that the seized pictures weren't relevant as evidence for prosecutors' suspicion of evasion of import tax, and that seizing the entire collection was disproportionate.
"Mr. Gurlitt and his defense team are well aware of the moral dimension of this case," said Tido Park, one of his lawyers. "However, the criminal proceedings are not the right place for moral categories."