BERLIN, April 5 (Xinhua) -- After a nationwide series of right-wing extremist threatening emails over the past year, a suspect had been identified, the chief of police and the attorney general's office in Berlin announced on Friday.

The police and public prosecutors shared a joint statement on Twitter saying that a man from Schleswig-Holstein had been arrested.

The man was suspected of sending threatening e-mails, some signed with "National Socialist Offensive" to authorities in Hamburg, Schleswig-Holstein, Baden-Wuerttemberg, and Brandenburg since April 2018.

Criminal police from Berlin and Schleswig-Holstein had searched an apartment in Schleswig-Holstein on Thursday afternoon and seized evidence, the statement said.

The confiscated evidence would be evaluated to substantiate the suspicions against the man, according to the joint statement.

At the same time, it would be determined whether the suspect was also the author of more of the 200 threatening letters that are the subject of ongoing investigations by the German authorities.

Over the past year, a series of anonymous e-mail messages threatening violence were sent to politicians, lawyers and other public figures across Germany.

At least 15 bomb threats from the sender "National Socialist Offensive" were reported to have been received by courts and judiciary centers since December 2018. In March, the Luebeck train station and the Gelsenkirchen tax office were evacuated as a precaution.