Twelve of the 13 people on board the Ukrainian Mi-8 helicopter that crashed into the Black Sea on March 27 have been killed, with the only survivor seriously injured, officials said.

The State Border Service helicopter was carrying 3 crew members and 10 passengers when it went down.

"One man has been found alive, but he is in serious condition. The bodies of 12 others were found near the crash site in the Black Sea," Sergei Astakhov, spokesman for the State Border Service, was quoted by the Interfax-Ukraine news agency as saying.

Emergency Situations Ministry spokesman Ihor Krol said the helicopter crashed some 40 minutes into a flight from the Black Sea port of Odessa to the nearby Zmeinyi Island at about noon.

A rescue team led by Emergency Situations Minister Volodymyr Shandra has rushed to the scene, Krol said.

"The cause of the crash is under investigation," he added.