Germany's foreign minister says his country will revise its travel advice for Turkey following the jailing of a German human rights activist who has no ties to the country.
Sigmar Gabriel said that the jailing of Peter Steudtner suggests that something similar could happen to any citizen.
Mr Gabriel also said he does not see how the government can continue guaranteeing companies' investments in Turkey in the absence of "legal security" and will have to consider what it does about export guarantees.
He added that Germany also wants to discuss pre-accession funding to Turkey from the European Union.
AP