Japan and Russia have agreed on the return of three bodies found on the coasts of the Russian-controlled Kunashiri Island and Sakhalin Island after a Japanese tour boat sank in April.

The tour boat "Kazu I," carrying 26 people, sank off Shiretoko Peninsula in the northern Japanese prefecture of Hokkaido. Fourteen people have been confirmed dead. Twelve remain unaccounted for.

Two bodies were found on the coast of Kunashiri Island in May, and another was discovered on the shore of southern Sakhalin in June.

Kunashiri is one of four Russian-held islands Japan claims as an inherent part of its territory. It says the islands were illegally occupied after World War Two.

The two governments have been engaged in discussions to arrange for the handover of the bodies through diplomatic channels.

The Japan Coast Guard says that the governments agreed that a Coast Guard vessel will be dispatched to the port of Korsakov in southern Sakhalin for the handover.

Officials say the Russian foreign ministry contacted Japan's foreign ministry on Tuesday. The handover is expected to take place as early as September.

DNA tests conducted by Russian authorities found they matched three of the people who were aboard the tour boat.

Japan plans to conduct further DNA tests to confirm their identities once they are returned.