The detention hearing was held on Sunday afternoon at Ystad District Court.
"The court has decided to detain the captain of the ship in accordance with the prosecutor's arrest request," the press service wrote in a text message.
The man is suspected, on probable cause, of aggravated use of a false document.
The Coast Guard boarded the ship on Thursday on suspicion that it was sailing under a false flag in Swedish territorial waters.
The captain was arrested the following day and is suspected of several crimes, including operating an unseaworthy vessel.
The ship is on the EU sanctions list. In recent years, the ship, which flies the Comoros flag (an archipelago near Madagascar), has transported oil products between Russia and Brazil, according to the Coast Guard.
Sea Owl 1 has also been banned from use by the Swedish Transport Agency and is not allowed to sail further.
A Russian captain of the bulk carrier Caffa, which was boarded outside Trelleborg on March 6, has already been taken into custody. He is also suspected of using a false document.
