Germany's opposition piled pressure on Chancellor Angela Merkel's government Wednesday in a widening row over a controversial treason probe targeting bloggers who had written about Internet surveillance.

In an affair that Tuesday claimed the scalp of the chief prosecutor, critics are now asking why ministers allowed Germany's first media treason investigation in half a century to go ahead in the first place.

Leftist opposition parties have demanded a parliamentary inquiry and the resignation of domestic security agency chief Hans-Georg Maassen, who had filed the treason complaint against persons unknown in May.

The investigation accuses the blog Netzpolitik.org (Net politics) of revealing "state secrets" by publishing plans by the domestic security agency to step up monitoring of the Internet and social media.

News of the investigation last week sparked protests from other journalists who condemned the case as an attack on press freedom and an attempt to intimidate investigative reporters.

The charge of treason -- to reveal state secrets to the detriment of the nation and to aid a foreign power -- carries between one year and, in very serious cases, life in jail.
Questions of state surveillance, including the NSA scandal revealed by fugitive US intelligence contractor Edward Snowden, are hotly debated in Germany, a country with raw memories of fascist and communist dictatorships.

As the Netzpolitik case rapidly turned politically toxic -- sparking a Twitter storm and a Berlin street rally at the weekend -- Justice Minister Heiko Maas distanced himself, voicing doubt the documents were indeed state secrets.

With Merkel's backing, his ministry urged chief prosecutor Harald Range to wind back the case.

Range, aged 67 and a year from retirement, shot back Tuesday, openly accusing the ministry of "an intolerable encroachment on the independence of the judiciary". Maas fired him several hours later.

- 'Facts on the table' -

Germany's opposition parties, the Greens and the far-left Linke, on Wednesday aimed their sights on Maas, security agency chief Maassen and his boss, Interior Minister Thomas de Maiziere.
"This is far from over," said Greens leader Simone Peter, demanding answers from the ministries about when the probe was launched and why.

"We want the facts on the table," she said. "This has the calibre of a government scandal. That's why the chancellery owes us some answers too."

The Bild newspaper commented that "Maas has not emerged unscathed from this skirmish. He should have told the chief prosecutor long ago that he did not have his blessing for this investigation."

Linke lawmaker Harald Petzold demanded explanations from the government, and the resignation of Maassen, who is head of the domestic security agency called the Federal Office for the Protection of the Constitution.

"All of this happened back in May, and now they all claim they didn't know about it, they were surprised by it, they are suddenly voicing their concern," said Petzold.

Merkel's spokeswoman reiterated Wednesday that the chancellor supported the justice minister's decision, while the interior ministry said the security agency chief had acted "correctly".
The German Journalists' Association meanwhile again demanded that "the criminalisation of the two journalists Markus Beckedahl and Andre Meister must end immediately."

Netzpolitik itself published a statement of solidarity signed by dozens of activists, journalists and academics -- among them Wikileaks founder Julian Assange and Glenn Greenwald, who has worked closely with Snowden.

"Charges of treason against journalists performing their essential work is a violation of the fifth article of the German constitution," they wrote. "We demand an end to the investigation into Netzpolitik.org and their unknown sources."