Oil giant BP is understood to have taken out an injunction against a Greenpeace ship headed for the Cromarty Firth.
Greenpeace has claimed the North Sea oil firm served the injunction to its Arctic Sunrise vessel as it reached port in Sunderland.
The 949-tonne icebreaker ship is due to sail for Scotland to support the ongoing occupation of the rig by Greenpeace activists.
The climate group say the injunction is to “prevent it from disrupting the transportation or operation of the oil rig”.
The campaign group has occupied the BP-contracted Paul B Lloyd Jr rig in the Cromarty Firth since Sunday.
The rig is owned by US firm Transocean.
BP chose not to comment on the situation, but it is understood that it considers the legal action a “precautionary measure” against any potential action by Greenpeace.
Greenpeace also claim that BP has taken out an injunction against another ship, the Esperanza, which is currently within UK waters.
In addition, BP are understood to have taken out a further injunction against Greenpeace UK itself.
The six-day standoff between the two organisations is understood to have cost BP close to £1 million in rig rates and other additional costs.
It’s understood that the 92 crew members on the rig have had to stay in the accommodation unit most of the week for safety reasons.
Greenpeace UK executive director John Sauven said: “The Arctic Sunrise has a history of standing up to oil drillers in every corner of the world, from the Arctic to the Gulf of Mexico, where it documented the massive damage caused by BP’s Deepwater Horizon blowout.
“We won’t be cowed by the oil giant’s legal threats.
“BP is using every legal means available to stop us, and we’ll be using every peaceful means available to stop them.
“This is now the frontline of the climate emergency, and the very future of our living world is at stake.
“Allowing BP to carry on with business as usual is not an option. We won’t give up until BP have ditched fossil fuels and fully switched to renewables.”