BOMBS intended to blow up a plane leaving Sydney were allegedly set to explode over the Blue Mountains, in what would have been Australia’s most catastrophic terror attack.

Amer Khayat, one of three brothers accused of trying to plant bombs disguised inside a Barbie doll on an Etihad Airways flight out of Sydney last year, allegedly told Lebanese police the devices had been fitted with self-timers that would explode after 20 minutes.

By this point, the plane would have been just west of the Blue Mountains.

Lebanese police claimed he told authorities the bombs never made it onto the plane because Etihad said the doll, which weighed 3.5kg, was too heavy to be taken as hand-luggage.

The 40-year-old father-of-two has since retracted his confession, telling News Corp Australia from Central Prison in east Beirut that he is “not a terrorist” and “wants to go home”.

The Roumieh facility is one of the world’s most dangerous and holds suspected Islamic terrorists.

His case has been adjourned until July 30.

To read more on the full interview with Amer Khayat go to the Daily Telegraph

Amer Khayat, his three brothers and another Sydney relative allegedly planned to detonate bombs hidden in a Barbie doll and a meat grinder on a Dubai-bound Etihad flight on July 15 last year.

Hidden in hand luggage, the self-timed bomb inside the Barbie doll was allegedly set to detonate a second bomb inside a meat grinder, killing 400 passengers and crew.

It would have been Australia’s most catastrophic terror attack, and the world’s biggest airline disaster in three decades, outstripping the 239 victims who died on MH370 in 2014.

Last August, Lebanese Interior Minister Nohad Machnouk said the plot “probably” would have been successful had the weight limit not been an issue.

He said the bombs had been sent back to the would-be attacker’s home in Australia.

He also said the second bomb was to serve as a back-up in case the first failed, and was to be detonated by one of the brothers who was supposed to be the suicide attacker.

Amer Khayat is the only member of the alleged “Barbie bomb” plot in custody in Lebanon who will likely be hanged or face a firing squad, The Australian reported in March.

Authorities detained Amer Khayat last year after the Sydneysider and dual Australian-Lebanese citizen made several trips to the Lebanese city of Tripoli, where he was to be married at his family home.

But his multiple journeys and quick divorce prompted suspicions.

When authorities questioned him, Amer Khayat allegedly revealed that he had attempted to smuggle the two bombs aboard the flight.

The plot was allegedly made in Raqqa where relatives had been fighting for Islamic State.

A third brother Tareq, an ISIS commander, was understood to be hiding in Syria, but his family in Lebanon said they believe he was killed fighting for the terror group in Iraq.

Last August, Mr Machnouk said Lebanese police had been tracking his movements since he moved to Raqqa.

Australian authorities were initially unaware of the plot until they received a tip-off from Israel’s military intelligence 11 days later.

In raids across Sydney last July, Amer’s brothers Khaled, 52, and Mahmoud, 32, were arrested and charged with two counts of allegedly planning a terrorist attack.

The raids also targeted members of the Merhi family, who are relatives of the Khayats, but none were charged.

Israeli intelligence corps claimed its “exclusive intelligence” had helped thwart the alleged attack.

Australian police investigated the fifth alleged “Barbie” plotter, but found there was not enough evidence to charge him.

However, all five men are accused in Lebanon of participating in terrorist activities, being part of a terrorist group and scheming to commit mass murder.

Sister-in-law Hiyam Khayat denied the Australian police version of events, saying they had “clean records in Australia”.

“Khaled bought the meat-grinder and all of the sudden gives it to Amer?’’ she told News Corp.

“If they wanted to do this thing, wouldn’t they just have paid the $7 for the excess luggage?”