ANKARA — A cargo ship carrying grain from a Russian-occupied region of Ukraine has been detained by Turkish customs authorities, according to Ukraine's ambassador to Turkey.

Vasyl Bodnar says, "We have full co-operation. The ship is currently standing at the entrance to the port, it has been detained by the customs authorities of Turkey".

We've tracked the Russian-flagged ship, the Zhibek Zholy, on its route from the Ukrainian port of Berdyansk, to Karasu on the Turkish Black Sea coast.

It is not clear where its cargo came from or how it was obtained, but Russia has been accused of stealing grain from areas of Ukraine it controls — allegations Russia denies.

Berdyansk is in Ukraine's southern Zaporizhzhia region, on the Sea of Azov.

News of the ship's departure from Berdyansk was announced on social media app Telegram by Yevhen Balytskyi, who was recently appointed by Russia as governor of the occupied areas of Zaporizhzhia.

Balytskyi said 7,000 tons of grain would be sent to "friendly" countries.

He added that ships from Russia's Black Sea Fleet would be "ensuring the security" of the journey, and that the port had been cleared of sea mines.

He later edited the post, taking out references to the ship's cargo and destination.

A video news report about the departure of the ship has also been shared on several pro-Kremlin Telegram channels showing it along with a Russian naval vessel in a harbour, which was identified as Berdyansk by the reporter.

Comparing the video footage with satellite imagery of the port, we have been able to confirm that it was filmed in Berdyansk.

The weather conditions in the video and the angle of the shadows along the harbour suggest it was filmed on the morning of 28 June.

Some features along the ship's hull, such as its name, were blurred out in the video. But we have confirmed that the ship that left Berdyansk is the same one now lying off the Turkish coast, based on images from the Telegram posts as well as eyewitness accounts given to a Ukrainian shipping expert.

We have also been able to track the earlier movements of the Zhibek Zholy as it made its way towards Ukraine to pick up its cargo.

On 22 June it travelled from Turkey, dropping off its cargo at the Russian port of Novorossiysk. As it then approached the Ukrainian coast, its tracking signal was lost - suggesting it had been switched off.

The signal only reappeared on 29 June as it headed back south away from the Ukrainian coast. This tracker also reports the depth at which the ship lies in the water - and it indicated that the ship had taken on cargo.

Michelle Bockmann, a markets editor at Lloyd's List Intelligence, believes this is "suspicious" behavior.

She says many cargo ships turn off their trackers for part of their journeys in the Sea of Azov, but most resume their transmissions when they reach their intended port.

It's not clear whether the ship intends to unload its cargo in the Turkish port of Karasu or continue its journey south through the Bosphorus Strait to an, as yet, unknown destination.

The registered owner of the Zhibek Zholy, a Kazakh-based company called KTZ Express, has told the Reuters news agency that the ship has been chartered by a Russian company. It added that it was consulting the parties involved and would abide by all sanctions and restrictions. — BBC