Aribert Heim, one of the most wanted Nazi criminals, has been dead since 1992, German's ZDF television reports.
It says Heim, known as "Doctor Death" lived under a pseudonym and died in Egypt's capital, Cairo, BBC reported.
ZDF says it found Heim's passport and his other personal documents in a hotel where he lived.
Heim was a concentration camp doctor and was accused of killing hundreds of concentration camp victims, using horrific medical experiments.
Leading Nazi hunter Efraim Zuroff from the Simon Wiesenthal Centre said he had not seen the documents found by ZDF.
But he added that if confirmed, the news would be "earth shattering", the Associated Press reports.