Prosecutors on Tuesday appealed a March 28 Tokyo District Court ruling that cleared hemophilia expert Takeshi Abe of professional negligence charges stemming from the AIDS death of one of his patients.

The prosecutors filed the appeal with the Tokyo High Court, against the lower court decision that Abe, once Japan's top hemophilia expert and former vice president of Teikyo University, was not criminally responsible for the death of a male hemophiliac who was contaminated with unheated blood-clotting agents tainted by HIV in 1985.

The ruling said it was impossible for Abe, 84, to foresee the danger of the unheated blood product at that time.

The court said the standards to be applied to Abe over whether he is responsible for negligence are same as with other hemophilia experts, who also administered unheated blood products.

In the trial prosecutors had claimed Abe gave instructions to administer the agents despite being aware of the danger, and demanded a three-year jail term.