The trial of suspected Nazi war criminal Sandor Kepiro, accused of mass killings in Serbia in 1942, resumed Thursday with the hearing of a witness who said his grandmother was killed in the raid.

The witness, a history professor who requested anonymity, testified that his grandmother had been murdered by troops under Kepiro's command.

However he conceded never having seen Kepiro either around the family home or elsewhere, and that he knew of the one-time gendarmerie officer only from the press.

The witness, who was aged 10 in 1942, said his family had left his ill grandmother behind when they were ordered by armed soldiers to appear before a civilian and military panel during the raid in Novi Sad, a Serbian town then occupied by Hungarian troops.

When they were released and returned home, they discovered traces of "blood, bone fragments... and brains," the professor recalled.

"My uncle was shouting for half an hour: they killed my mother!"

The family later learnt that the grandmother's body had been left for some time in front of the house, but it was never recovered, the witness went on.

Due to the frailty of the defendant, the judge adjourned the trial after the testimony until June 20, when the further schedule will be revealed.

According to the defence, the verdict is expected in early July.

Kepiro -- possibly one of the last Nazi war crime suspects to be tried -- faces a life sentence for his alleged participation in the Novi Sad raid by Hungarian forces between January 21 and 23 in 1942, in which more than 1,200 Jews and Serbs were murdered.

Specifically, the 97-year-old is accused of ordering the rounding up and execution of 36 Jews and Serbs as head of one of the patrols involved in the raid.

The 97-year-old was tracked down in Hungary by chief Nazi hunter Efraim Zuroff of the Simon Wiesenthal Center in 2006.