"We need to be clearer than we have been until now so those responsible in Ankara understand that such policies are not without consequences", Gabriel told reporters.
According to the Turkish government, Fethullah Gulen and his network orchestrated the failed coup of July 15, 2016, which killed 249 people and injured 2,000 others. In June, Germany made a decision to withdraw its troops from Turkey's Incirlik air base and move them to Jordan in protest at the repeated delays that members of the German Bundestag had encountered in trying to visit the facility.
Turkey and Germany have been locked in a number of diplomatic disputes, including Turkey's way of handling the aftermath of a failed coup in July previous year, which has sparked massive criticism in Germany.
Turkish President Recep Tayyip Erdogan proposed an exchange deal to Germany.
Turkey in February arrested, on similar charges, German-Turkish journalist Deniz Yucel of Die Welt daily and is holding several other German citizens. Germany is Turkey's largest trading partner, while ethnic Turks make up Germany's largest minority.
He said: "Unfortunately we have constant cause to talk to Turkey about civil and press freedoms". So far this year, bookings from Germany have accounted for about 10 percent of Turkey's tourists. The Association of German Chambers of Commerce (DIHK) has already commented on Gabriel's speech, saying current developments in Turkey are likely to affect doing business in the country.
"Today's remarks by German Foreign Minister Sigmar Gabriel were the latest and an unacceptable example of this one-sided distorted approach", the ministry said.
He also said it was "great political irresponsibility" to warn German citizens against traveling to Turkey.
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The NATO allies have also clashed over thwarted visits by German lawmakers to troops stationed at Turkish bases.
In response, the Turkish Foreign Ministry claimed Germany was interfering with Ankara's national affairs and judiciary system.
Turkish-German relations have been severely strained after Turkey detained six human rights activists, including a German citizen Peter Steudtner, earlier this week accusing them of assisting the activity of terrorist groups.
The measures being considered include withdrawing export guarantees and pre-accession funding to Turkey from the EU, Gabriel said.
"I therefore cannot see how we, as the government, can still guarantee corporate investments in Turkey when we are seeing arbitrary, politically-motivated confiscations [of property] there and arbitrary deportations for political reasons", he underlined.
In June, authorities detained Amnesty's local board chairman, Taner Kilic, along with 22 other lawyers, also for suspected links to Gulen, who has condemned the coup attempt and denied any involvement.
The list included chemicals giant BASF, which confirmed it was on a list that had been passed to it by German police, but declined to comment on the allegations.
Turkish deputy prime minister Mehmet Simsek said on Thursday the reports were untrue.
Schaefer also mentioned the ongoing detention of German reporter Mesale Tolu, who has been in Turkish custody since April.