Marine accident investigators are set to begin a sonar survey of a fishing boat which sank in Loch Fyne with the loss of two of its crew.

The Nancy Glen capsized in the Argyll and Bute loch on January 18 and is now lying at a depth of around 140m.

Two of its crew, Duncan MacDougall and Przemek Krawczyk, are presumed dead following the incident.

The Marine Accident Investigation Branch (Maib) is expected to begin a sonar survey of the wreck this week in order to establish why the two men died.

However the UK government agency does not plan to raise the wreck, and a campaign to retrieve the bodies of the two crew members has raised more than £200,000.

A third member of the crew, John Miller, managed to survive the disaster after being rescued from the water.

The Maib will use underwater robots to search the Nancy Glen following the sonar search by the NLV Pharos.

Last week, Nicola Sturgeon pledged the Scottish Government's help in efforts to recover the bodies of the two fishermen.

Responding to a question from Conservative MSP Donald Cameron, she said: "I am very clear as First Minister, the Scottish Government are very clear, that one of those considerations should be the desire-the understandable desire-of the families to recover the bodies of their loved ones.

"The Scottish Government will offer whatever support we can.

"I obviously cannot preempt the conclusions the MAIB will come to but I can assure the Member, and the chamber, that we will do everything possible not just to support the families but to ensure they can recover bodies of their loved ones."