German investigators believe the suspect, last known to be living in Poland, was one of the divers who planted an explosive device on a pipeline running from Russia to Germany under the Baltic Sea in September 2022.

On Wednesday, De Spiegel magazine cited security sources as saying the suspect was believed to have left Poland.

Another man and woman - also Ukrainian diving instructors - have been identified in the German investigation into suspected sabotage but no arrest warrants have so far been issued for them, according to newspapers SZ, Zeit and broadcaster ARD.

It remains unclear who was behind the explosion that destroyed three of the four pipelines, which became a symbol of Germany's dependence on Russian gas after the conflict in Ukraine broke out in February 2022. Russia and the West have accused each other of being responsible for the pipeline explosions, with each side denying involvement.

A Swedish investigation found traces of explosives on several objects collected at the scene, confirming that the explosion was intentional.

In January 2023, German investigators raided a ship they said was likely used to transport explosives and told the United Nations they believed the divers involved in the sabotage were trained to attach devices to pipes at depths of around 70 to 80 metres.

Nguyen Khanh (according to Guardian, ARD, SZ)