The MV Parida was transporting a cargo of cemented radioactive waste from Scrabster in northern Scotland to Antwerp, Belgium, when the fire broke out in one of its funnels.

The blaze was put out by the ship's crew of 15 and the anchor was dropped following the turn off of the engine to stop the vessel's drift, however 52 workers were airlifted off Beatrice as a precaution.

The ship was subsequently towed to a secure pier at the Port of Cromarty Firth by a commercial operator, despite the Aberdeen coastguard sending two emergency tugs to assist.

The 3000 litre cargo was reportedly undamaged.

"It's a very small quantity that's on board this vessel, and it's stable. We're not talking about huge amounts of radioactive waste," a spokeswoman for the UK coastguard told Reuters.

The waste was from the Dounreay experimental nuclear power plant, which has been on a decommissioning schedule since 2011.

As part of the shut-down, 150 tonnes worth of intermediate level waste is being shipped back to Belgium in 21 shipments over four years, with the waste having originally being sent to Dounreay for reprocessing.

The Scottish government is closely monitoring the incident, according to reports.