TOKYO (AFP) - A court condemned Japan's defence ministry on Wednesday for hiding evidence that proved there was a link between a young sailor's suicide and his vicious bullying by a senior officer.

Tokyo High Court ordered the government and the officer to pay more than US$700,000 (S$880,000) in compensation to the family of a 21-year-old man who killed himself by jumping in front of a train in 2004.

The officer, who was serving aboard the warship Tachikaze, reportedly shot at his young charge with an airgun and forced him to buy pornographic movies.

Neither man has been publicly identified.

In the original legal case, a lower court said the defence ministry was not responsible for the man's death, but ordered it to pay 4.4 million yen (S$53,970) to his family for the officer's hazing and extortion.

But when the victim's family appealed to the higher court, a navy whistleblower revealed that the ministry had hidden key documents showing the results of an in-house investigation conducted following the sailor's suicide.

The ministry had insisted the documents, in which fellow sailors testified on the hazing and extortion of the senior naval officer and said the depressed young man's suicide had seemed imminent, had been destroyed.

Tokyo High Court said the ministry had illegally concealed "significant evidence for the court procedure". A ministry spokesman earlier told AFP that the official in charge had "apologised for testifying not based on facts".

The senior officer was discharged from the navy after a court found him guilty of assaults on underlings, but his 30-month prison sentence was suspended for four years.