'The Hokuo Maru from the Hokkaido fisheries inspectorate came to the handover point,' Vladimir Nosov, a local foreign ministry official based on the island of Sakhalin, was quoted as saying.

'A representative of the Japanese foreign ministry signed a document on the handover of Japanese citizens. There were no complaints against the Russian side,' Mr Nosov said.

The handover took place along the disputed sea border between Russia and Japan near Kunashiri, a Russian-ruled island claimed by Japan, near where the men were arrested on Dec 13.

A Russian court earlier found the four fishermen guilty, fined them and ordered that their four fishing boats be returned to their owners.

The fishermen paid the fines, Russian news agencies reported.

Russia and Japan frequently have disputes over fishing rights.

In August 2006, a Russian coastguard boat opened fire on a Japanese fishing vessel, killing one of its four crew members and further straining relations.

The countries have never signed a peace treaty formally ending hostilities after World War II, as Japan lays claim to four islands off its northern coast which Soviet troops seized days after Tokyo's surrender in 1945. -- AFP