A man has told a Sydney murder trial of buying a suitcase and setting it on fire with his friend's body inside.
Brendon Gallo said he did what he was told because he feared brothers Azam Charbaji, 26, and Haysem Charbaji, 24, "would turn on me".
The 21-year-old sobbed in the NSW Supreme Court on Monday as he told the jury of seeing Dane McNeill being bashed, stabbed and force-fed Xanax tablets, and of later hearing screams and thuds.
The brothers have pleaded not guilty to the July 2014 murder of Mr McNeill, 20, whose smouldering body was found inside a suitcase at Picnic Point in Sydney's southwest.
The then girlfriend of the younger brother, Lexy May Jamieson, 26, has denied being an accessory.
Mr Gallo said he, Mr McNeill and the brothers smoked the drug ice before returning to the apartment shared by Haysem Charbaji and Jamieson.
When Mr McNeill asked for money, saying he was going to be bashed if he did not pay a debt, the brothers punched him repeatedly, Mr Gallo said.
His friend screamed as he was stabbed in the lower back with a steak knife before a kitchen cloth was placed over the bleeding wound and Xanax tablets were forced into his mouth, he said.
He was placed in the laundry and tied up with duct tape before Mr Gallo was told to stay outside the door overnight while the others slept, he said.
In the morning, Mr McNeill was supported out to a car and taken to Azam Charbaji's house.
"Dane's level of consciousness was 75 per cent," Mr Gallo said.
They smoked ice before the brothers took Mr McNeill into the bathroom while Mr Gallo waited outside feeling "too scared to move".
After hearing his friend screaming and crying for help, Mr Gallo said he was told to get some more Xanax tablets "because of the screaming".
He saw Azam Charbaji retrieve a 20cm-long ratchet from a tool box and return inside, from where Mr Gallo heard "three bangs and more screaming".
Mr Gallo said he was later told to buy a large suitcase and when he walked back inside the house "there was this smell and there was Azam in the back room with Dane with sheets and another suitcase".
His friend was dead and was put into the bigger suitcase, which was put in a car boot, he said.
Mr Gallo said he was told to buy cleaning products used to clean the house and to buy kerosene which was mixed with petrol.
The suitcase containing the body was dragged to its final resting place and Mr Gallo poured the liquid onto it and set it alight, he said.
The trial is continuing.
