Navy divers on Sunday recovered the remains of the seventh of the eight crew members from a U.S. military Osprey aircraft that crashed off southern Japan during a training mission.

The Air Force CV-22 Osprey went down on Nov. 29 just off Yakushima Island in southwestern Japan while on its way to Okinawa. The bodies of six of the crew had since been recovered, including five from the sunken wreckage of the aircraft.

The U.S. Air Force Special Operations Command said in a statement that the body recovered by Navy divers was one of the two crew members still missing. The identity of the airman has been determined but the information is withheld until next of kin has been notified, the command said.

“Currently there is a combined effort in locating and recovering the remains of our eighth airman,” it said.

A week after the crash and repeated reminders from the Japanese government about safety concerns, the U.S. military grounded all of its Osprey V-22 helicopters after a preliminary investigation indicated something went wrong with the aircraft that was not a human error.

The U.S.-made Osprey is a hybrid aircraft that takes off and lands like a helicopter but can rotate its propellers forward and cruise much faster, like an airplane, during flight.

The crash raised new questions about the safety of the Osprey, which has been involved in multiple fatal accidents over its relatively short time in service. Japan grounded its fleet of 14 Ospreys after the crash.

Japanese defense officials say Ospreys are key to the country's military buildup especially in southwestern Japan, in the face of a growing threat from China. But the crash has rekindled worries and public protests in areas where additional Osprey deployment is planned.

Japanese residents and media have criticized Japan’s government for not pushing hard enough to get Ospreys grounded sooner or gain access to information about the crash.