ISTANBUL, Nov. 19 (Xinhua) -- One crew member died and two others were poisoned following a toxic leak on a Panama-flagged tanker in the Marmara Sea off Istanbul on Wednesday, local authorities said.

The Istanbul Governor's Office reported that the leak was detected at around 5:30 p.m. local time (1430 GMT) in the cold tank of the vessel Swanlake, located about two nautical miles south of Democracy and Freedoms Island. The exact substance involved in the leak has not been disclosed.

The tanker was carrying 13 Russian crew members. Evacuation operations were underway after the leak as emergency teams worked to secure the ship, according to the governorate.

No further information was provided regarding the vessel's cargo or destination, and an investigation into the cause of the leak is ongoing. Enditem