TOKYO. Sept 8: Japanese police arrested a senior naval officer today for passing defence secrets to a suspected Russian military spy, a police spokesman said, reports AFT.

Lieutenant Commander Shlgehlro Hagisaki. a 38-year-old member of the Maritime Self-Defence Force, was arrested just before dawn after about nine hours' interrogation, he said.

The Japanese naval officer was in a secret dinner meeting Thursday evening with the Russian embassy official when police took him in for questioning, Tokyo police spokesman Masatoshi Konomi told AFP.

Hagisaki broke down in tears when police in business suits surrounded the pair in the Tokyo restaurant and showed him the warrant, said a police investigator speaking on condition of anonymity.

The man later confessed to spying, he said.

T did not realise I was committing a crime. I thought it was part of my research work." he was quoted as telling police by Jijl

The Russian embassy official, who reportedly worked for the Russian military's Main Intelligence Administration (GRU), immediately claimed diplomatic immunity.

A Russian embassy official in Tokyo identified the Russian man as 44-year-old naval attache Captain Victor Bogatenkov, but declined to give further details.

Japan's government said the embassy refused a request for Bogatenkov to appear voluntarily before police. Police said they may ask the foreign ministry to expel him.

The arrest came just three days after a visit by Russian President Vladimir Putin, who met with Japanese Prime Minister Yoshiro Mori In a vain attempt to resolve a 55-year-old territorial dispute.

Four islands, known as the southern Kurils in Russia and the Northern Territories in Japan, were occupied by Soviet troops in the final days of World War II and a dispute over their ownership has blocked the signing of a peace treaty ever since.

"Unfortunately this case leads one to think that there exist in

Japan forces which are unhappy with the recent positive trends in Russian-Japanese relations." the Russian foreign ministry said.

The Tokyo Metropolitan Police’s security investigation unit had been watching Hagisaki since September last year when he was a chief navigator for a Japanese naval escort ship.

In March this year, he was moved into a new Job as a researcher on the former Soviet Union at the National Institute for Defence Studies, which examines Japan's defence strategies.

The pair had made contact about 10 times since December 1999 at bars, sushi shops and Chinese restaurants in central Tokyo which were crowed by office workers after work, aid the Japanese investigator.

The Russian embassy official, who had fluent Japanese, paid for thousands of dollars worth of food and drink in return for copies of documents marked "Secret and "Caution.“ which were not allowed to be removed from the defence Institute, he said.