MELBOURNE, Australia (AP) — The head of an inquiry into antisemitism in Australia on Tuesday said Jewish witnesses who appeared before it are facing online harassment and bigotry and issued a condemnation.

The Royal Commission on Antisemitism and Social Cohesion was created in response to two gunmen allegedly inspired by the Islamic State group slaying 15 people at a Sydney Hanukkah celebration in December. Royal commissions are Australia’s highest form of public inquiry.

The commission’s head, former High Court judge Virginia Bell, said Jewish witnesses who testified about their experiences of antisemitism since public hearings began on May 4 have been subjected to online “harassment and intimidation.”

“We have received reports from a number of witnesses concerning a dramatic increase in online hate messages after they have given evidence,” Bell said.

“Quite what this undiluted level of hatred and bigotry directed towards members of the Jewish community is thought to benefit by those who post these remarks is lost on me,” she added.

The commission was recording the “offensive social media posts,” Bell said, and in one case the harassment has been referred to police.

“The commission has, as one of its principal objects, understanding and assessing the lived experience of antisemitism by members of the Jewish community and it is being informed by conduct of this character,” she said.

The first two weeks of hearings scrutinized the nature and prevalence of antisemitism in Australia’s institutions and society.

During the first week of hearings, a 68-year-old man was charged with wearing a shirt emblazoned with a “prohibited Nazi symbol” outside the commission in Sydney, a police statement.

The design appeared to incorporate a Star of David superimposed over a swastika with the slogan: “Antisemitism. Proud to be accused. Speak up!”

The commission said in a statement at the time it was “appalled” that an “antisemitic shirt” had been worn in its vicinity. The commission assured witnesses that safety protocols were in place around the building.

“The royal commission is determined to investigate antisemitism in Australia without fear or intimidation,” the statement said.