He has been remanded in custody on suspicion of using a false document, a felony.
"There were no longer sufficient grounds for detention. The investigation has not been closed," says Public Prosecutor Agneta Roos.
The ship was boarded on May 3 while sailing into the Baltic Sea. The Coast Guard stated at the time that it had been following the ship for some time and that it had been on several sanctions lists, including those of the EU and the UK.
