The mystery concerning the identity of a man calling himself Clark Rockefeller, who is in custody for abducting his own daughter, may soon come to an end as a German man claims Rockefeller is his long-lost brother.

Alexander Gerhartsreiter said that his brother, Christian Karl Gerhartsreiter, left home at the age of 17 and lost contact with his family more than two decades ago.

“It seems you found my brother,” Alexander Gerhartsreiter said when he was handed a photograph of Rockefeller by a Boston Herald reporter who visited his home in Germany’s Upper Bavaria, The Associated Press reported. “It is really a shock,” he added, according to the same source.

Alexander Gerhartsreiter said his brother was born on February 21, 1961, in Siegsdorf, Germany. In 1978, he moved to the United States to study in Connecticut, but never came back. Furthermore, he hasn’t called his parents since 1985, when they last heard of him.

Investigators have been on the track of Rockefeller’s true identity since he allegedly kidnapped his 7-year-old daughter during a supervised visit on July 27 in Boston. However, he was caught a few days after the incident in Baltimore, where he had purchased an apartment and a boat. His daughter, Reigh Boss, was found safe and was shortly reunited with her mother, Sandra Boss.

Besides the kidnapping case, Clark Rockefeller has been named a “person of interest” in the mysterious disappearance of a California couple, The Associated Press reported. According to Los Angeles detectives, a man calling himself Christopher Chichester  lived on the property of Jonathan and Linda Sohus of San Marino, California. The two have been missing since 1985. Authorities now say that Clark Rockefeller’s fingerprints matched Chichester’s. Furthermore, police believe Chichester was one of the dozens of aliases used by Christian Gerhartsreiter.

What’s more, Steve Savio, 39, of Berlin, Connecticut, said on Thursday that he was absolutely sure that Rockefeller was the same guy who boarded with his family in 1980 using the name of Christian Gerhart Reiter.