VIENNA, Austria (AP) _ A conference opening Thursday will provide new evidence against a Viennese doctor accused of Nazi-era murders of disabled children, a city official said.

Sepp Rieder, the Vienna councilman responsible for public health, said Wednesday that the conference on Nazi euthanasia will increase pressure to reopen the case against Heinrich Gross, 83.

``He was a murderer,'' Rieder told reporters, but he did not say what the new evidence was.

Gross has argued he was not present at the Vienna neurological hospital in the 1940s when most of the children were killed.

His case has come to symbolize a fresh attempt by Austria to confront its Nazi past and decades of protecting those involved in atrocities.

Gross was formally charged in 1950 with the murder of hundreds of children at what is now Vienna's main psychiatric institute. But the case was thrown out on a legal technicality, and the state prosecutor's office inexplicably dropped the charges.

After the war, Gross went on to head the institute and was sought as an expert witness at trials into the 1990s. Gross, who lives just outside the capital, refuses to talk to journalists.

Legal authorities later redefined the killings as manslaughter, which has a 30-year statute of limitations, meaning Gross can no longer be convicted.

But prosecutors are considering a new trial on murder charges, which are not covered by a statute of limitations. Legal officials, speaking on condition of anonymity, said new investigations have uncovered evidence including Gross's initials or signature on a bottle of medicine given to a child who later died.

The investigations were launched after Vienna last year revealed hundreds of preserved brains taken from the children after their deaths and used in medical research well after World War II.

Though the brains had been displayed since the 1980s in a special memorial chamber in the psychiatric hospital, their existence had not been widely known.

This week's conference will include experts from the United States, Canada and Germany.

Austrians have been struggling to come to terms with their country's participation in Nazi crimes at least since 1988, the 50th anniversary of Hitler's annexation of Austria. That coincided with the furor surrounding then-President Kurt Waldheim and his concealed past as a soldier in the German army.

Austrians long were taught they were victims of Hitler's Germany, but many now realize their country must shoulder part of the blame for the Holocaust and other Nazi atrocities.