Argentina has ordered the seizure of assets belonging to foreign drilling companies operating in the vicinity of Falklands / Malvinas Islands, saying they have failed to obtain the necessary permissions from Buenos Aires to conduct exploration.

A federal judge in Tierra del Fuego, Lilian Herraez, has ordered authorities to seize the assets of five companies drilling for oil in the Falklands worth $156 mn. The measure was ordered following a request of a prosecutor from the Office of Economic Crime and Money Laundering (PROCELAC).

According to the prosecution, the order to seize assets was issued for “illegal activities of exploration, search and eventual extraction of hydrocarbons in proximity to the Falkland Islands” because the companies in question failed to obtain permits issued by “the competent authority in Argentina.”

According to a legal brief, the order involves halting the activities of the semi-submersible “Eirik Raude” rig and the floating dock“Noble Frontier”. Herraez also ordered the seizure of all vessels.

The five companies mentioned are: Premier Oil Plc, Rockhopper Exploration Plc, Falkland Oil and Gas Ltd, Noble Energy Inc and Edison International Spa. Three of them are UK based, one is American and the fifth is French-owned, based in Italy.

It remains unclear how these companies’ assets are supposed to be appropriated from territory officially under the jurisdiction and sovereignty of the United Kingdom. The companies in question do not generally hold any assets in Argentina or use Argentine waters, a source told Reuters.

However, the Argentine prosecutor’s office said it “had identified the assets of the foreign companies and discovered that one of them, the US firm Noble Energy, has a local office registered in Argentina.” Authorities will move to freeze those assets, it said.

READ MORE: British firms discover oil and gas off Falklands, Argentina threatens legal action

“The foreign ministry will be notified of the court order so that by diplomatic means and in compliance with international treaties it can be carried out,” the prosecutor’s office said in a statement.

In April, a group of British exploration companies found oil and gas in an area north of the Falkland Islands. The oil was discovered by the Eirik Raude floating drilling rig as part of an eight month exploration campaign. Argentina has predictably not been happy about the exploration activity, which is bound to further inflame tensions over the island’s disputed ownership.

In Argentina, the Falkland Islands are known as the 'Islas Malvinas.' The dispute between the UK and Argentina over the sovereignty of the islands has reemerged in recent years under President Cristina Fernandez de Kirchner.