On Saturday evening, the Oleg Naidenov with 72 crewmembers on board caught fire. The entire crew was rescued with no injuries reported. On Sunday, the trawler was tugged out to sea.
According to EFE news agency, the ship sank on Tuesday at 22:45 local time (20:45 GMT) in an area of the Atlantic where the seabed is 7,800-feet deep.
The ship had 1,500 tons of fuel on board.
Local Marine Rescue Service sent its personnel to check if an oil spill has occurred.