This undated photo that appeared in a German newspaper over the weekend shows a man identified as Christian Karl Gerhartsreiter.

Authorities are now speculating that the man could be Clark Rockefeller, who is accused of kidnapping his 7-year-old daughter on July 27 during a supervised visit in the Back Bay area.

Authorities captured Rockefeller in Baltimore, Md. on August 2, where he and his daughter were found living in a sparsely furnished apartment.