Australian police reveal alarming details about Sydney terror plot

Australian police have revealed alarming details about the terror plot to bring down a plane leaving Sydney for the Middle East.

They've revealed there was not one, but two planned attacks, and that a working bomb was taken to Sydney Airport long before police knew of any threat.

Father and son Klahed and Mahmoud Khayat faced court on Friday accused of Australian terror on a scale the country has never seen before.

Australian Federal Police Deputy Commander Michael Phelan said their plot was "one of the most sophisticated plots that has ever been attempted on Australian soil".

Police revealed there were two separate plots, one of which came dangerously close to completion.

They say the Khayats turned a meat grinder into a fully functioning bomb with explosives and parts sent by post from Turkey under the instruction of Islamic State.

Mr Phelan said they were "being inspired and directed directly from ISIL in Syria and this advice was coming from a senior member of Islamic state".

On July 15 they brought the bomb to Sydney Airport, where they tried to check it onto an Etihad AIrways flight.

They reportedly gave up because their bag was too heavy at check-in, and never made it to airport security.

But police say the bomb was ready to go and was enough to cause significant damage.

"We really could well have had a catastrophic event in this country."

Police allege the men then hatched another plan - they were working to build a chemical weapon to poison passengers on flight out of Sydney with toxic hydrogen sulphide gas.

One man is still in custody whilst another was released, but police say they're confident the threat is over and they've recovered all components of potential bombs.

It's a wakeup call for Australia and although Islamic State is a world away in Syria, its influence is reaching much closer to home.