Ehime Prefectural Police do not intend to punish officers who investigated the case of a 51-year-old man who last month was acquitted after being detained for more than a year on a false charge of theft, officials said Friday.

The man, a resident of Ehime Prefecture who has asked the press to withhold his identity, has indicated he will file a damages suit against the state for wrongly accusing him of stealing 500,000 yen from an acquaintance's bank account.

The inspection office of the prefectural police force concluded Friday that the officers involved in the man's case failed to conduct an adequate backup investigation. Their conduct, however, cannot be called illegal, the office said.

The Ehime man was arrested in February 1999 on suspicion of stealing a personal seal from a friend's house in Uwajima, Ehime Prefecture, before withdrawing 500,000 yen from a co-op bank between October 1998 and January 1999.