A poorly discarded cigarette probably caused a fire that sank a prawn trawler in the Moray Firth, accident investigators say.

The Karinya went down off Fraserburgh on October 4 last year but its five crew managed to escape on a life raft.

The blaze began in the cabin of the Karinya and spread so quickly the crew were forced to abandon the boat without life jackets.

Marine Accident Investigation Branch (MAIB) experts said a "poorly discarded cigarette end left in the cabin" was probably responsible.

The crew were rescued unharmed by the passing fishing boat Pleiades but the Karinya was lost.

The RNLI was ordered to stop fighting the fire due to the risk of explosion from the 10,000 litres of fuel aboard the boat and it went down shortly after 9pm, eight hours after the fire began.

MAIB investigators concluded: "Karinya foundered following a fire that almost certainly started in the cabin.

"The fire's ignition source has not been determined. However, it is probable that the fire resulted from a poorly discarded cigarette end that was not fully extinguished and was left in the cabin or fell or was blown down the internal stairway and through the open cabin door.

"It was fortunate that Pleiades was fishing in close proximity to be able to receive Karinya's skipper's radio call and to render prompt assistance.

"The rapid and controlled abandonment of Karinya demonstrates the benefit of conducting regular emergency drills and ensuring safety equipment is maintained and ready for immediate use."

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