A German journalist from public broadcaster ARD was denied entry to Turkey because of "security reasons," Turkish Deputy Prime Minister Numan Kurtulmus said on Wednesday.
Journalist Volker Schwenck, who was denied entry on Tuesday, also lacked press credentials to work in Turkey, Kurtulmus charged.
Chancellor Angela Merkel expressed concern about the incident.
Schwenk has travelled to rebel-held areas in northern Syria through Turkey. While Turkey backs the Syrian opposition and long tolerated this practice, it has recently clamped down and is largely not letting journalists travel to Syria any longer.
Turkey and Germany are engaged in a diplomatic stand-off that resulted last week in Merkel authorizing criminal proceedings against a comedian who insulted President Recep Tayyip Erdogan.
In March, Hasnain Kazim, a reporter for news magazine Der Spiegel, was denied accreditation by the Turkish authorities and was forced to leave the country, joining a growing list of journalists who have either been deported or denied accreditation.
Reports Without Borders, an advocacy group, ranks Turkey 151, out of 180 countries, on its Press Freedom Index. The government insists there are no restrictions on the press.