Mr McNeill had been punched, stabbed up to a dozen times and forced to swallow the drug Xanex in a Sydney apartment but remained alive for many hours.

His mother Rebecca sent Facebook messages to his friends and drove to different places looking for his white Subaru Impreza.

But she would never see him alive again.

On Monday the NSW Supreme Court heard that a garbage truck driver later found Mr McNeill's charred remains inside a suitcase at a reserve in Picnic Point in Sydney's south west.

During her opening address to a jury, Crown prosecutor Margaret Cunneen SC, said that two brothers – Haysem and Azam Charbaji – had murdered Mr McNeill as part of a joint criminal enterprise in July 2014.

Ms Cunneen explained that the brothers had murdered Mr McNeill following a dispute over a $3000 debt involving his on-off again girlfriend Jade Patterson.

She said the brothers had attacked Mr McNeill in a Heckenberg apartment, shortly after Mr McNeill had also asked them for a loan.

"There were indications in the lungs that death did not occur instantaneously but over a period of time," she said.

Ms Cunneen also indicated that the Crown's star witness Brendan Gallo would explain how he and Haysem Charbaji's girlfriend – Lexy May Jamieson – had been at the Heckenberg unit at the time Mr McNeill had been attacked on Friday, July 18.

She said Mr Gallo was expected to give evidence about how he was ordered to guard Mr McNeill in the laundry overnight.

"Brendan Gallo will tell you that he heard Dane murmuring during the course of the night and he will tell you that he helped Ms Jamieson clean up some sprinkles of blood that had gone onto the lounge," Ms Cunneen said.

The following day – Saturday, July 19 – Mr McNeill was allegedly moved to a house in Cartwright where one of the Charbaji brothers spoke to him in a lounge room.

"That's it, we just want our money, call your man and you can go," one of the brothers allegedly said.

It will be alleged that Azam Charbaji was later seen holding a ratchet he had retrieved from a tool box.

"Brendan Gallo heard a couple of bangs and screaming from with inside the house," Ms Cunneen told the court.

The jury of seven women and five men were also told of how after Mr McNeill had died, his body was stuffed into a black and orange suitcase, which had been bought from Kmart.

Ms Cunneen said she also expected to call a witness who would give evidence about how Ms Jamieson had come to him for advice on what to do with Mr McNeill's body.

"What do I do with it [the body] ?" Ms Jamieson allegedly asked.

She allegedly also spoke about how she had helped to clean up the blood in her apartment.

"We scrubbed it … we scrubbed the f--- out of it," she allegedly said.

During a brief address to the jury, defence barrister Keith Chapple, SC said his client Azam Charbaji had nothing to do with the assault of Mr McNeill "at all".

The Charbaji brothers are both on trial charged with one count of murder and Ms Jamieson for being an accessory after the fact to murder.

The trial continues before Justice Stephen Rothman.