Eleven Australians took part in the Global Sumud Flotilla to Gaza in May when they were detained in international waters at gunpoint, before being imprisoned and eventually deported from Israel.
Members of the group claim they experienced violence, sexual assault and abuse while in the custody of the Israelis.
Some of the Australian participants met with Foreign Minister Penny Wong and senior members of the Australian Federal Police on Monday afternoon at Parliament House.
During the meeting, they pressed for commitments from the federal government, including the expulsion of Israel's ambassador to Australia.
Juliet Lamont, who alleges she was raped by an Israeli soldier, said the AFP representatives in attendance agreed to an independent investigation into their allegations.
"She (Senator Wong) said she believed us," Ms Lamont told reporters following the meeting.
"You could hear a pin drop in there. It was harrowing. It was acutely emotional.
"Every woman that was there, and I think it was maybe 10, they all believed us and came up to us at the end and thanked us for sharing our harrowing testimony, said that we were really brave and want to support us in the investigations."
An AFP spokesperson said the organisation had begun inquiries into allegations made by a representative of the group.
"The AFP engages with a victim-centric, trauma-informed approach," the spokesperson said.
"The AFP will provide an update at an appropriate time."
Senator Wong has previously told parliamentary hearings she believed the testimonies of the Australian activists.
Neve O'Connor, who participated in the flotilla, said the group wanted to see "strong accountability".
"We would like to see a government that acts on behalf of their Australian citizens who have been abused, tortured, and raped, and actually act on our benefits," she said.
The group said they were "absolutely appalled" at the consular assistance they received when they arrived in Istanbul from Israel.
Israel's National Security Minister Itamar Ben-Gvir attracted global condemnation after he posted a video of himself taunting detained activists as they knelt on the ground with their hands zip-tied behind their backs.
The Israeli military's bombardment of Gaza has killed more than 72,000 people and destroyed the territory's infrastructure, according to the United Nations World Food Program.
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