German authorities have issued an arrest warrant for a Ukrainian man on suspicion of being part of a team that blew up the Nord Stream gas pipelines in the Baltic Sea, according to local media reports.

The man, a diving instructor identified only as Volodymyr Z, is last believed to have lived in Poland, and is alleged to have dived 80 metres to the seabed at night to plant explosive devices on the pipelines, which ran from Russia to Germany, in September 2022.

The explosive devices detonated on 26 September, seven months after the start of the full-blown Russian invasion of Ukraine. Four large gas leaks were discovered on both Nord Stream pipelines close to the Danish island of Bornholm, putting the pipelines out of use.

Seismic institutes had registered two underwater explosions on the pipelines, which had been built between 2010 and 2012 to transport Russian gas to Germany. At the time of the explosion they were not in operation, but had contained gas.

According to reports in Süddeutsche Zeitung and Die Zeit, as well as the broadcaster ARD, Germany first asked Poland to arrest the man in June, but he is thought to have gone underground, according to security sources cited in the reports.

The German prosecutor general’s office, which has been investigating the case even after Denmark and Sweden dropped their respective inquiries, has declined to comment.

Polish authorities confirmed on Wednesday that a European warrant for his arrest had been received. The national public prosecutor’s office said in an email to the news agency AFP: “Ultimately, Volodymyr Z was not detained, as he left the territory of Poland at the beginning of July this year, crossing the Polish-Ukrainian border.”

The media outlets also identified another man and a woman – who are also Ukrainian diving instructors – as having allegedly been involved in the attack, though no further arrest warrants have been issued for them.

Earlier on the investigation focused on a sailing yacht called Andromeda on which traces of the explosive HMX, also known as Octogen, were found in July 2023. The boat was rented in Germany by someone using a Google account registered in Ukraine. The crew members reportedly used false identities, including a Romanian and Bulgarian passport and that of a Ukrainian soldier who denies involvement and whose identity is believed to have been stolen.

The yacht, a 50ft Bavaria Cruiser, started out in Rostock harbour and stopped off on the German island of Rügen, the islands of Bornholm and Christiansø in Denmark, followed by Sandhamn in Sweden and Kołobrzeg in Poland before returning to Rostock.

Volodymyr Z was identified after the white Ukrainian-registered Citroën he was driving on Rügen was caught speeding by a police camera, which captured the image of his face on 8 September 2022.

Despite evidence that Volodymyr Z may have had the backing of high-ranking military officials, there is no suggestion that the Ukrainian president Volodymyr Zelenskiy was aware of the attack or that it was state-sanctioned.

Russia and the west have blamed one another for being behind the destruction of the pipelines, which stood as an ugly reminder for many of German dependence on Russian gas. Everyone accused has so far denied involvement.