A man’s body was recovered from the vessel last night, and his next of kin were informed of his death.
Police say the incident occurred around 8.40pm, with all other crew members on the boat reported safe and uninjured.
The incident took place north of Cape Wrath, famed for its lighthouse, in Sutherland in the highlands.
Detective Inspector Scott Macdonald said: “Our investigation is at an early stage and we are working with the Marine Accident Investigation Branch to establish the full circumstances.
“A report will go to the Procurator Fiscal in due course.”