Germany summons Turkish envoy over Osman Kavala sentencing
"I can tell you that we summoned the Turkish ambassador to the foreign ministry today and made the government's position very clear once again," the spokesman told a regular government press conference.
A Turkish court on Monday sentenced Kavala to life in prison on controversial charges of trying to topple the government. He had already been held without conviction for more than four years.
Some of Turkey's main allies and rights campaigners swiftly condemned his sentencing.
German Foreign Minister Annalena Baerbock called for his immediate release.
His jailing was "in flagrant contradiction to the rule of law standards and international obligations to which Turkey is committed as a member of the Council of Europe and a candidate for EU accession," she added.
Campaigner and intellectual Kavala, 64, was jailed over his involvement in a wave of anti-government protests in 2013.
The court also jailed seven other defendants for 18 years each on the charge of aiding the attempt to overthrow the government.
The 2013 protests were sparked by government plans to demolish an Istanbul park and grew into a broader movement against Erdogan's rule.