As journalists lounged on leather sofas outside the closed doors of a parliamentary conference room on Wednesday afternoon, few held hopes that a legal affairs committee inquiry going on inside would lead to a major breakthrough. The inquiry, one seasoned political correspondent said, would likely just peter out.

He might be proved right. A parliamentary committee looking into the chief federal prosecutor's treason allegations against two journalists seems to have left several questions unanswered, several legislators told reporters after the meeting - not least because two leading figures had failed to make an appearance. Both Interior Minister Thomas de Maiziere and Hans-Georg Maassen, the head of German intelligence services, sent representatives instead of showing up to testify themselves.

In July, Public Prosecutor Harald Range launched a treason investigation into the Netzpolitik.org journalists Markus Beckedahl and Andre Meister, months after they reported on secret government plans to expand online surveillance. Netzpolitik specializes in covering online privacy and digital culture, and, true to their mission, the journalists had published a report about plans for heightened Internet surveillance by German intelligence services, using confidential documents to make their case. Range opened his probe following a criminal complaint filed by Germany's domestic intelligence agency, the BND.

On Wednesday, Renate Künast, a member of the opposition Greens and the chairwoman of the Bundestag's legal affairs committee, said the treason allegations were "clearly aimed at intimidating media organizations - maybe even parliamentarians." She said Netzpolitik was singled out because it had published the confidential documents in their entirety: "That was obviously the last straw." But, she said, the probe "totally backfired."

Did Merkel's office know of the probe?

Opposition politicians claim that both the Chancellery and Interior Ministry knew of the investigation - and maybe even prompted the BND to file its criminal complaint - but the absence of Interior Minister de Maiziere and BND boss Maassen made it difficult to pursue that line of questioning.

The treason investigation prompted widespread criticism from free-speech advocates who accuse the authorities of curtailing expression and failing to protect whistleblowers. Many also accuse the government of singling out journalists while notably failing to investigate accusations of mass surveillance by the US National Security Agency.

Ultimately, Social Democratic Justice Minister Heiko Maas weighed in, questioning the decision to open the investigation in the first place and finally firing Range after the prosecutor accused him of political interference, which Maas has denied.

According to members, the parliamentary committee has not determined whether Maas put pressure on Range to drop the case, which the prosecutor's office ultimately did.

Meanwhile, a separate investigation into how the documents were leaked to the bloggers continues.

Künast said her committee would invite de Maiziere and Maassen to another hearing: "Eventually, they'll have to make an appearance."

Parliamentarians, it seems, are committed to ensuring that the investigation does not just peter out, as many journalists still fear.