Ed Husic is calling on the federal government to prepare targeted sanctions against people in Israel's government overseeing the military campaign in Gaza against Hamas.
Israel blocked aid and medical supplies entering the strip for 11 weeks and has begun letting in small amounts - according to global news agencies - which international aid organisations say are a drop in the ocean of what is needed.
More than two million people face starvation and an already anaemic health system in the war zone is at risk of a complete collapse without medical supplies, amid repeated Israeli strikes against healthcare facilities.
Asked whether the war in Gaza had the hallmarks of a genocide, Mr Husic said it was "hard to avoid making a conclusion in your own mind that it will probably end up being called that".
Israel has strongly denied accusations of genocide made by South Africa to the International Court of Justice.
In January 2024, the world court issued a ruling mandating that Israel take measures to prevent acts that could be genocidal, prevent incitement to genocide and ensure the delivery of humanitarian aid to Palestinians.
While acknowledging the court, Mr Husic said that fact that it had been "required or forced, if you will, to indicate that there are probable grounds, speaks volumes".
A response has been sought from the Israeli Ambassador to Australia, Amir Maimon.
More than 53,000 people in Gaza have been killed, according to local authorities, after Israel retaliated following an attack by Hamas on October 7, 2023, that killed 1200 people and resulted in 250 hostages being taken, according to Israel's tallies.
Mr Husic said Australia needed to be prepared to put in place targeted sanctions against Israel's Netanyahu government and Israel Defence Forces for breaches of humanitarian law if the full blockade wasn't ended.
Israel's government has said it's withholding aid to pressure the designated terrorist organisation Hamas into releasing the remaining hostages.
Canada, France and the UK last week warned of "further concrete action" if Israel doesn't halt its military campaign and lift aid restrictions.
"I think they are well advanced in their preparations and we should be prepared to move rapidly," Mr Husic told reporters in Canberra on Tuesday.
The former cabinet minister also called for Hamas to be held to account for the atrocities it has committed, and to release the remaining hostages.
Mr Husic said the "biggest failing of the Netanyahu government and the IDF is their absolute failure to distinguish between civilian and combatant".
"The notion that there'd be a condition applied that people won't get aid in the form of food or medicine until these hostages' release, I mean, that is not just wrong, it breaches humanitarian law," he said.
Using starvation as a method of warfare is a war crime, according to international law experts.
Mr Husic also expressed concerns about reports Israel has blocked some medical professionals from entering Gaza.
English orthopaedic and pediatric surgeon Ana Jeelani, who previously worked in Gaza, said she was recently blocked from entering the strip and other surgeons had been as well.
"What's happening in Gaza currently is an atrocity and they need hands on deck," she told ABC Radio.
The comments come a day after Prime Minister Anthony Albanese said Israel's actions in Gaza were completely unacceptable and that "the idea that a democratic state withholds supply is an outrage".
He added Israel's explanations were "completely untenable and without credibility".
