The Turkish Foreign Ministry has summoned the German ambassador.
The Foreign Office in Berlin had previously called in the Turkish ambassador on Friday because of the internationally criticized judgment against the prominent cultural promoter Osman Kavala.
Kavala and seven other defendants were sentenced last Monday in Istanbul in connection with the 2013 Gezi protests critical of the government.
Kavala received a life sentence for attempted coup.
A ministry spokesman said that the Turkish ambassador was "made very clear" about the position of the federal government during the talks.
The federal government demands the immediate release of Kavala.
Chancellor Olaf Scholz (SPD) had sharply condemned the verdict against Kavala via a spokesman as “a devastating signal for Turkish civil society as a whole and the rule of law situation in Turkey”.
Turkish diplomatic sources said on Friday evening that the German Ambassador Jürgen Schulz had been informed that the Turkish Ambassador in Berlin was condemned.
The German ambassador was also informed that the Turkish judiciary was independent and that attempts at intervention from outside were rejected.
Kavala, 64, was found guilty of financing nationwide demonstrations allegedly aimed at overthrowing the government.
The cultural patron rejects the allegations.
Critics and opposition parties accuse the judiciary of taking after President Recep Tayyip Erdogan.
The European Court of Human Rights has already ruled that previous trials against Kavala were politically motivated.