The Berlin public prosecutor's office suspects that information about an arrest warrant against the conspiracy narrator Attila Hildmann was passed on inadmissibly from within its own ranks.
The public prosecutor announced on Tuesday that it was being investigated against unknown persons for violating official secrets.
The "Süddeutsche Zeitung" had previously reported.
Hildmann has been in Turkey for months, so an arrest warrant on the urgent suspicion of sedition cannot be carried out.
According to the public prosecutor's office, the 40-year-old has both German and Turkish citizenship.
His return is currently unlikely.
But there is no connection between the passing on of information and Hildmann's flight, it said.
He had already "long" gone abroad before the arrest warrant was issued.
More than 1000 statements by Hildmann are checked
In the preliminary investigation against Hildmann, the Berlin prosecution checked more than 1000 statements.
In addition to the suspicion of sedition, it is also about the suspicion of public incitement to criminal offenses and resistance to law enforcement officers.
Formerly known as a vegan cookbook author, Hildmann calls himself “ultra-right” and a conspiracy preacher.
Hildmann appeared during protests against the corona protective measures.
The police in Brandenburg had initially secured evidence during a search of his apartment.
In December, a court order in Berlin obtained that the public prosecutor's office could evaluate laptops, cell phones, memory cards and USB sticks.
The investigations were bundled in Berlin.
Justice Senator Dirk Behrendt (Greens) justified this with effective criminal prosecution.
Several preliminary investigations from Brandenburg had been handed over to the authorities in the capital.