The Moscow City Court on Friday sentenced Latvian national Dmitry Savins to seven years in a high-security prison for leading a pirate attack on the Arctic Sea vessel.
The Arctic Sea went missing in the Atlantic on July 24 while carrying a $2 million shipment of timber from Finland to Algeria and was intercepted by the Russian Navy off West Africa on August 17, when eight alleged hijackers were arrested.
The prosecutor had asked for nine years while Savins' defense lawyers thought their client would get six.
Savins is the second defendant in the case to fully admit his guilt. Earlier, Andrei Lunev also pleaded guilty to the hijacking and was sentenced to five years.
The other six suspects maintain their innocence and have been remanded in custody until August 18 while the investigation continues.
In a plea bargain, Savins testified against the alleged mastermind behind the attack, Eerik-Niiles Kross, the former head of Estonia's foreign intelligence service.
Savins said Kross had acted in collusion with another organizer of the attack - Sergei Demchenko, a German-based businessman.
Savins said the attackers were to get 20,000 euros each if the operation was a success, while he as "gang leader" expected a reward of 200,000 euros.
He said Kross had run into financial problems as a result of the global economic crisis and decided to solve his problems by seizing a commercial vessel and holding it to ransom.
Savins said it had taken him 10 months to pick the members of his group, one of the grounds for selection being past criminal record.
He said the Arctic Sea had been chosen because of its low speed and its "accessibility."
He said one reason the plan went wrong was that the ship's owner, as well as its insurer, Renaissance Group, refused to pay the ransom and played for time while the hijackers "kept drinking and getting demoralized."
Russian investigations committee spokesman Vladimir Markin said investigators were looking into Savins' testimony.
Kross denied the allegations.
"The allegations that I ordered the seizure of the Arctic Sea are at variance with the facts," he was quoted as saying by Estonian daily Eesti Paevaleht. "I believe that these fabrications are connected to my consultation services for Georgia on security matters. Georgia is not Russia's best friend."
Kross owns Trustcorp, a consultancy firm that has in the past few years been working with Georgian state agencies.
Latvian prosecutors said there was no evidence linking Kross to the Arctic Sea seizure.
The ship's disappearance, which triggered a major international search effort, raised suspicions about it carrying a "secret cargo" of drugs or weapons. Russian authorities have denied the rumors, saying the vessel was hijacked by criminals who demanded a ransom.
Russia's special investigations committee announced last year that all 14 crewmembers of the Arctic Sea had been formally recognized as victims of a pirate attack.
MOSCOW, June 11 (RIA Novosti)