Described by both Russia and western European countries as an act of sabotage, the explosions marked a major escalation in the Ukraine conflictand squeezed energy supplies on the continent.
No one has taken responsibility for the blasts and Ukraine has denied any role.
Germany's top prosecutors' office said Polish police had acted upon a European arrest warrant for Volodymyr Z that it had issued.
Its statement said the qualified diver was one of a group of people who were suspected of renting a sailing yacht in the German Baltic Sea port of Rostock and planting explosives on the pipelines, running from Russia to Germany, near the Danish island of Bornholm on September 26, 2022.
He faces accusations of conspiring to commit an explosives attack and of "anti-constitutional sabotage," the prosecutors added.
Volodymyr Z's lawyer Tymoteusz Paprocki said he was detained in a town near Warsaw.
In a statement, Paprocki said: "My client has done nothing wrong and pleads not guilty. My client has not committed any crime to the detriment of Germany."
Paprocki said Volodymyr Z's defence would fight against his transfer to Germany, arguing that the execution of the European arrest warrant against him was inadmissible given Russia's war in Ukraine.
"The attack on Nord Stream infrastructure concerns one of the pipeline's owners, Gazprom, which directly finances the military operations in Ukraine," he said.
Gazprom is Russia's state gas company.
If he is extradited by Poland, Volodymyr Z would be brought before an investigating judge with Germany's Federal Court, the German statement said.
In August, Italian police arrested a Ukrainian man suspected of co-ordinating the attacks.
The man, identified only as Serhii K, plans to take his fight against extradition to Italy's highest court after a lower court ordered his transfer toGermany.
The blasts wrecked three out of four Nord Stream pipelines, which had become a controversial symbol of German reliance on Russian gas in the wake of the Russian invasion of Ukraine.
The United States and the NATO military alliance have called the incident "an act of sabotage" while Russia has blamed the US, the United Kingdom and Ukraine for the blasts which largely cut Russian gas off from the lucrative European market.
All countries have denied involvement.
Germany, Denmark, and Sweden all opened investigations into the incident, and the Swedes found traces of explosives on several objects recovered from the explosion site, confirming the blasts were deliberate acts.
The Swedish and Danish investigations were closed in February without identifying any suspect.
