This marks the start of proceedings regarding the suspect's impending extradition to Germany, the Croatian broadcaster HRT reported.
The suspect - described as a scuba diver by German prosecutors who have identified him only as Vladimir Z - was arrested in the early hours on Wednesday in a hotel in the Croatian coastal city of Pula on a European arrest warrant issued by Germany.
Matija Milos, the Ukrainian's lawyer, said his client would challenge the impending extradition through legal channels and pursue all available remedies.
Under Croatian law, the proceedings - including any appeal - must be concluded within 60 days.
The charges against the man include jointly causing an explosion using explosives.
Vladimir Z is alleged to have been one of the divers who attached the explosive charges to the pipelines in the North Sea.
The explosions - described by Russia and European countries as sabotage - damaged the Nord Stream 1 pipeline, a vital route for Russian gas exports to Europe, as well as the Nord Stream 2 branch, which had yet to enter service.
According to the Croatian police, the suspect was arrested at tourist accommodation in a resort on the southern outskirts of Pula.
The resort is also hosting a Hollywood film crew which is currently filming the Nord Stream attacks as a fictional political thriller.
Directed by the US director Doug Liman, the film features Hollywood stars Sean Penn and Adrien Brody.
The suspect is reported to have been staying in Pula as part of this film crew, registered at the accommodation under a false name.
According to the London Times newspaper, he was working on the production as a consultant.
The man was previously arrested in Poland at the end of September last year, also based on a European arrest warrant issued in Germany.
However, the government in Poland, a close ally of Ukraine, refused to extradite him.
It is considered unlikely that Croatia will follow suit.
with Reuters
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