Prosecutors say vessel was carrying humanitarian aid and was inspected unlawfully on November 22 in Mediterranean Sea without consent of flag state, Turkey.
Turkish prosecutors have launched an investigation into the illegal search of a Turkish commercial freighter by the crew of a German frigate participating in a European Union mission to enforce an arms embargo on Libya.
Turkey has protested the incident on the Mediterranean Sea, insisting personnel from the German frigate Hamburg, commandeered by a Greek official, illegally searched the Libya-bound freighter Rosaline-A on November 22.
In a brief statement announcing its investigation, the Ankara Chief Prosecutor's office said the search was conducted without "Turkey's authorisation and against international regulations."
The probe is not expected to lead to arrests or the extradition of officials involved in the search of the aid-carrying ship.
Use of force
The Hamburg is part of the controversial European Union's Operation Irini, a mission launched in March with the goal of enforcing the United Nations' arms embargo on Libya and tasked with inspecting vessels thought to be carrying weapons to and from Libya.
German officials said the order to board the Rosaline-A came from the mission's headquarters in Rome and that Turkey objected while the inspection team was on the freighter.
Turkey says the search was "unauthorised and conducted by force" and insisted that its objections prior to the search were ignored.
Biased Irini operation
According to the law of the sea, the consent of the flag state must be obtained for the personnel to board the ship in order to search the ships.
Despite warnings, the Hamburg Frigate's soldiers searched the merchant cargo vessel which was carrying humanitarian aid, food, and paint.
Turkish has slammed the "biased" Irini operation, saying it ignores weapons heading to Libya's illegal militias.
"The neutrality of Operation Irini, which the EU launched without consulting with the legitimate Libyan government, our country, or NATO, is currently under discussion," Foreign Ministry spokesman Hami Aksoy said earlier this week.
"This double-standard and illegal treatment applied to ships transporting from our country to Libya are never acceptable," he said.
Turkey supports a UN-backed government in Tripoli against rival forces based in the country's east.
It has complained that the EU naval operation focuses its efforts too much on the Tripoli administration and turns a blind eye to weapons sent to the eastern-based militia led by warlord Khalifa Haftar.