Several insurers of the Nord Stream natural gas pipeline have argued in a London court that the 2022 attack on the pipeline was a direct outcome of the Russia-Ukraine conflict. These firms are attempting to avoid paying approximately €580 million (around $684 million) in compensation for the pipeline explosions.

Nord Stream AG is suing Lloyd’s and Arch Insurance over the September 2022 blasts, which damaged the Russian-owned gas pipelines running along the Baltic Sea floor to Germany. The explosions—which no country has claimed responsibility for—largely severed Russia’s natural gas supplies to Europe, marking a major escalation in the conflict and triggering energy supply shortages.

At the request of German prosecutors, Italy and Poland have separately arrested two Ukrainian individuals after traces of explosives were found on a vessel linked to the incident. Russia has accused Ukraine of orchestrating the attack, though Kyiv has repeatedly denied any involvement.

The lawsuit, filed by Switzerland-based Nord Stream AG, centers on damage to the Nord Stream 1 pipeline and asserts the company’s right to nearly €580 million in compensation.

Lawyers representing Lloyd’s and Arch Insurance argued that Nord Stream’s insurance policy excludes coverage for damage caused by war or acts carried out under government orders. Simon Salzedo, counsel for the insurers, stated in court filings that geopolitical experts agree the explosions could only have been executed by state actors from Ukraine, Russia, or the United States, or by Ukrainian “sub-state actors” with state assistance.

During proceedings at London’s High Court, the insurers will seek to demonstrate that the 2022 explosions were linked to the war in Ukraine or were ordered by a state. Investigators from Germany and Sweden have spent years attempting to identify those responsible. Italy extradited a Ukrainian citizen to Germany last year, but a Polish court refused to extradite another suspect.

Salzedo noted that insurers do not need to prove who carried out the attack or why, only that state involvement was highly probable or that the blasts were influenced by the Ukraine war. Lawyers for Nord Stream countered that no expert has been able to confirm which government, if any, was responsible, and emphasized that “the only certain fact at present is that the Ukrainian state has repeatedly and explicitly denied any involvement.”