Germany's chief federal prosecutor is accusing the government of interfering in a much-criticized treason investigation against two journalists.

News of the probe against two journalists for website Netzpolitik.org emerged last week. At issue are two reports revealing the domestic spy agency's plans to expand surveillance of online communication. The agency filed a criminal complaint.

The Justice Ministry has questioned prosecutor Harald Range's decision to open the investigation. Range said Tuesday that the ministry ordered him to withdraw an independent expert from the case who determined that the leaked documents in the reports were a "state secret," one requirement for a treason case.

Range said he complied but "influencing investigations because their possible result does not appear politically opportune is an intolerable intervention in judicial independence." The ministry didn't immediately respond.