An Australian father of two facing a possible death penalty in Lebanon for an alleged Islamic State plot to blow up a flight from Sydney has accused Lebanese authorities of bashing him, fabricating evidence and forcing him to sign a false confession.

Mr Khayat says he was interrogated for 65 consecutive days in Lebanon and that authorities made him sign a blank document, which became a confession.

Amer Khayat, 39, gave an emotional and animated testimony for more than an hour overnight in Lebanon’s military court in Beirut, where he stands accused of planning to blow up the Etihad flight to Abu Dhabi with 400 people on board in the sky above Australia on July 15 last year.

Australian Federal Police have said the Australian-Lebanese dual citizen had “no idea” he was carrying a bomb hidden in a meat grinder inside his hand luggage, but Lebanese authorities accuse him of being a willing suicide bomber.

Mr Khayat’s brothers, Mahmoud and Khaled, are due to stand trial in the New South Wales Supreme Court next year accused of planting the bomb in his hand luggage as he set off from Sydney for Lebanon via Abu Dhabi.

The two brothers are accused of making the bomb using material that was posted to them, in a plot that was allegedly instigated by a third brother, Tarek Khayat, an Islamic State commander who was captured in Iraq earlier this year.

The plan was allegedly only aborted when an Etihad check-in officer at Sydney Airport ordered Amer Khayat to remove items from his hand luggage because it was overweight.

Australian authorities only became aware of the alleged plot when they received a tip-off from Israel’s military intelligence 11 days later.

Following the arrest of Mahmoud and Khaled Khayat in Sydney, then Deputy AFP Commissioner Michael Phelan said their brother Amer was an unwitting participant in the alleged Islamic State plot.

“We will be alleging that the person who was to carry the IED [improvised explosive device] on the plane had no idea they were going to be carrying an IED,” Mr Phelan said in August last year.

On Monday evening (local time) in Beirut, Amer Khayat told Lebanon’s military court he had no idea about the plot until three weeks after he landed in Lebanon, when he read about the arrest of his brothers in the media.

“I have nothing to do with all that,” he told the tribunal. “I was living a free life in Australia, clubbing.”

Amer Khayat was arrested in Tripoli, in northern Lebanon last August, 10 days after the arrest of his brothers in Sydney.

‘They made me sign a blank paper’

He cried as he told the military court overnight he had been interrogated by Lebanese authorities for 65 days straight.

He said he was slapped by interrogators and forced to sign a blank document, which was later filled in and turned into a false confession.

“They made me sign a blank paper,” he said.

“After hours of interrogation, they took me upstairs and forced me to sign a paper.”

Police at a crime scene after four men were arrested in counter-terror raids across Sydney.

Amer Khayat said he was in such shock when he read the alleged confession that he had to be hospitalised.

“When I first read my file, I ended up for three or four days at the hospital,” he said. “Everything I read was false in the file.”

Amer Khayat described himself as a former ice user with mental health issues who had been estranged from his brothers for long periods of time.

Police raided homes across Sydney allegedly connected to the bomb plot. Photo: AAP

When asked by the military tribunal’s chairman, General Houssein Abdallah, why he had “Islamic-related” photos on his phone, Amer Khayat said they were planted there by Lebanese authorities.

“They took away my phone, deleted girls’ and boys’ pictures and added these pictures that I have never had before,” he said.

Amer Khayat was also asked about a handwritten letter to his daughter saying he wanted to commit suicide.

“It’s not my handwriting,” he said. “You can verify that. The officer wrote a letter in English and forced me to sign it.

“They would do anything to lock me up because they are after Tarek Khayat.”

The Barbie doll bomb

Amer Khayat’s older brother Tarek was a senior Islamic State commander who was wanted by Lebanon for allegedly trying to set up an IS emirate in the country’s north and for leading his followers in battles against the Lebanese army in Tripoli in 2014, shortly before he fled to Syria.

According to Lebanese authorities, Amer Khayat also confessed to trying to smuggle a bomb in a Barbie doll onto the plane.

Overnight he told the court he never brought the doll to the airport.

The ABC understands Mahmoud and Khaled Khayat will not face any allegations in Australia that they tried to plant a bomb in a Barbie doll.

Mahmoud and Khaled Khayat have pleaded not guilty to two charges each of planning or preparing to commit a terrorist act.

The case against Amer Khayat will return to Lebanon’s military court in Beirut in September.

Human rights groups have previously accused Lebanese authorities of torturing suspects and forcing them to provide false evidence.

-ABC