The most senior Australian member of ISIL, former Kings Cross nightclub bouncer Mohammad Ali Baryalei, has reportedly been killed in the Middle East.

Baryalei is believed to have died in fighting around four or five days ago.

He was accused of being the mastermind of the recent plot to execute random members of the Australian public on camera, which was foiled in the nation's largest ever counter-terrorism raids in across Sydney on September 18.

Foreign Minister Julie Bishop said the government is trying to confirm Baryalei's death.

Mohammad Baryalei is believed to be ISIL's most senior Australian member. (ABC) (ABC)

News of the death circulated on social media around 13 hours ago.

Before travelling to Syria and joining the jihadist front, Baryalei was a preacher in the Street Dawah movement, which tried to convert Australians to Islam.

A friend and Street Dawah colleague, Yassin Ali, wrote on Facebook that Baryalei had been "martyred".

Yassin Ali's post. (Facebook)

British-based researcher Shiraz Maher, from the International Centre for the Study of Radicalisation at Kings College in London, also tweeted the reports.

It is believed Baryalei is responsible for recruiting at least half of the Australians fighting with ISIL in the Middle East.

More than 800 police swooped on homes across Sydney on September 18 after police allegedly intercepted a call from Baryalei to Sydney man Omarjan Azari, 22, ordering the plan to go ahead.

It is believed that at least 15 Australians have been killed in the conflict against IS since it began.

"Australians who leave this country to fight in Iraq and Syria are putting themselves in mortal danger," Ms Bishop told the National Press Club today.

"They have a great risk of being killed. They are committing offences against Australian laws."

Baryalei's family fled Afghanistan as refugees when he was just a baby and he was brought up in Sydney's northwest suburbs.

He is reported to have abused drugs and had mental illness issues before finding radical Islam.

Australian jihadists Khaled Sharrouf and Mohamed Elomar. (Supplied)

Among those Baryalei is alleged to have helped join ISIL are Sydney men Khaled Sharrouf and Mohamed Elomar.

Sharrouf posted graphic images of his young son holding a severed head to Twitter in August, captioned "that's my boy!".

A former actor, Baryalei also had a cameo in the Underbelly series as a paramedic.

The news of Baryalei's reported death comes as a Senate bill was passed today giving spy agencies more power to stop Australians heading overseas to join terrorist organisations.

The government legislation prohibits travel to terrorist hot spots without a valid excuse and makes it illegal to promote or encourage terrorism.

Visiting a no-go zone designated by the foreign minister is punishable by 10 years in prison.

The bill passed the Senate today with bipartisan support, after the government agreed to multiple amendments recommended by a bipartisan joint parliamentary committee. The bill now heads to the lower house.