"Statements, which are covered by the German freedom of expression laws, can lead in Turkey to occupational restrictions and criminal proceedings," it warns.
Germany revised its travel advisory to Turkey on Saturday, warning that statements protected by freedom of expression laws in Germany may not be so in Turkey.
"It cannot be ruled out that Turkish authorities will take further action against representatives of German media and civil society organisations," the updated travel advisory reads.
"Statements, which are covered by the German freedom of expression laws can lead in Turkey to occupational restrictions and criminal proceedings," it adds.
The travel advisory highlights that a number of German nationals have been "arbitrarily detained" over the past two years after being suspected of supporting the movement of exiled Muslim cleric Fethullah Gulen — which Turkish authorities believe to be behind the July 2016 coup attempt and consider a terrorist organisation.
Holidaymakers who have attended meetings organised by groups banned in Turkey risk being detained, the Foreign Ministry warned, adding that simply sharing or liking a social media post critical of the government can result in a multiple-year prison sentence if convicted on charges of "presidential infidelity" or "propaganda for a terrorist organisation."
It also noted that German journalists had been denied entry or accreditation without explanation, which Foreign Minister Heiko Maas denounced as "unacceptable."
"My Turkish colleagues know that," Maas said on Twitter, calling for a "working dialogue."