Oslo - Exhuming the Norwegian grave of a man who died in 1945 may offer clues to his then claims that he was a missing Austrian archduke, news reports said Thursday.

Norwegian heirs to Dr Hugo Kohler have applied for permission to exhume his grave to retrieve DNA in an attempt to prove his claims that he was really archduke Johan Orth who went missing in 1890, the Norwegian daily Faedrelandsvennen reported.

Knut Harald Saeth, church board chief in the Norwegian town of Kristiansand, granted the permission after consulting the Ministry of Culture and Church Affairs.

The archduke's estate included the tourist attraction Schloss Orth, a castle in Austria and other properties worth some 3.5 billion kroner (503 million dollars), the report said.

Kohler's claims, made on his death bed, have been questioned by some researchers. Austrian officials were also to attend the opening but no date has been set for the exhumation as the ground is frozen. (dpa)