The suspect had a price of more than 1 million dollars put on his head.
Germany has detained a suspected leader of DHKP-C militant group, the Federal Prosecutor's Office announced on Saturday.
The DHKP-C is an outlawed ultra-leftist group listed as a terrorist organisation by Turkey, Britain, the European Union, and the United States. The suspect's detention came after Turkey's President Recep Tayyip Erdogan accused Germany of harboring terrorists last month.
Musa Asoglu, a 55-year-old Dutch citizen, was detained in Hamburg, according to Anadolu Agency. The precise day of his arrest is unknown.
Asoglu had a price of one million dollars put on his head. Turkish Interior Minister branded him in the category "red", which refers to the most wanted, in its "wanted terrorists" list.
"We are worried that Germany, which has been taking terrorist organizations like the PKK, DHKP-C under its wing, is now becoming a backyard for FETO," Erdogan said in a speech in Ankara last month.
DHKP-C participated in a number of terror attacks in Turkey, including a suicide bombing at the US embassy in Ankara in February 2013. The group was also behind the killing of prosecutor Mehmet Selim Kiraz at a courthouse in Istanbul in March 2015.