Professional chef Jacob Greig - charged with allegedly murdering teenage boy on camping trip at Wilton - is accused of making horrifying threat before slashing the 15-year-old with a knife

The man charged with the murder of a 15-year-old boy found dead in bushland allegedly told the teenager 'I'm going to chop your f***ing hand off' before slashing him with a knife, a court has been told.

Emergency services rushed to Wilton Park Rd in Wilton about 7.25am on Saturday and found the Picton boy's body lying in bushland adjacent to the road.

Jacob Greig was arrested after he attended Narellan Police Station shortly after 4pm on Saturday following a public appeal for information.

He was charged with murder and refused bail to appear before the Parramatta Local Court on Sunday.

Greig appeared via a video livestream, with three of his family members attending in person.

The court was told the 15-year-old boy had tried to open the rear passenger door of a vehicle Greig was in, with video and audio of the incident capturing the teenager saying 'I'm trying to get home'.

At some point Greig got out of the vehicle, with Magistrate Robert Rabbidge saying footage had allegedly captured Greig saying 'I'll f***ing get you good'.

He then allegedly said 'I'm going to chop your f***ing hand off', the court was told.

Greig allegedly told police he 'slashed the victim before returning to the vehicle', Mr Rabbidge said.

However the court was told footage allegedly showed Greig pursuing the victim on foot.

'The facts indicate that the matter prior to injury ... The accused had threatened to kill the young person and chop his hand,' Mr Rabbidge said.

He said the boy was 'bleeding profusely' after allegedly being slashed with the knife.

'It appears a very strong case, I acknowledge that having slashed the young person with the knife causing the victim to sustain ... severe laceration in the right forearm ... victim starts to bleed profusely,' the magistrate said.

The boy allegedly tried to jump on the car as it drove off, with his friends finding him dead the following morning.

The court was told a trail of blood extending about 30m towards the end of Wilton Rd was found.

'Much would depend on the post mortem, which is yet to take place, but I do note the facts where it says at 7.30 the following morning the victim's friends have walked from the camp ... found the [alleged] victim covered in blood,' Mr Rabbidge said.

He said there is 'nothing more serious than the alleged murder of a 15-year-old'.

'The facts are quite extraordinary and seem to show a considerable amount of powerful evidence.

'It's clearly an extraordinary case ... Mr Greig is looking at many decades in prison,' the magistrate said of the allegations, if proven.

'I must do my duty to the community and refuse him bail.'

Police prosecutor McCormack said a bloodstained knife was found in a bin.

'I know that the [alleged] victim ... was covered in a significant amount of blood in a grass area,' Mr McCormack told the court, with a trail of blood 'extending possibly 30m down the roadway ... down the end of Wilton Park.'

Greig's aunt and two other family members appeared distressed during the proceedings, with the aunt breaking down in tears just outside the courtroom.

Defence lawyer Javid Faiz proposed a home detention condition, noting that the circumstances are 'tragic'.

'I respectfully submit this, it's a tragic incident whatever's occurred, and it's tragic it's occurred to a 15-year-old,' Mr Faiz said.

He questioned whether the cause of death is the alleged offending by Greig, noting 'some impact has obviously occurred' after the boy jumped on the car, driven by another person.

'We know that there's some blood ... about 30m from the roadway, we can see that there's blood, it's just not clear ...(whether it is a) result of laceration or result of impact,' Mr Faiz said.

'I propose a home detention condition which means he can't leave his residence in absence of his aunty.'

Greig's partner is expected to give birth to their child in a month, with his partner suffering health conditions including autism and panic disorder.

Greig is employed as a chef at Bargo Sports Bar while his partner is unemployed.

'Instructions I've been provided is that he provides the sole care for the family,' Mr Faiz told the court.

'If he's not to be released today, Your Honour, that family will be impacted.

'Lot of stress in the family as a result of this, and he's the sole provider.'

Greig was refused bail and is next set to front a Campbelltown court on January 8, 2025.

Superintendent Tim Calaman told reporters on Saturday a group of about 12 teenagers had been camping in the area overnight.

None are accused of wrongdoing.

Police believe the incident occurred on Friday evening, but they were not notified until 7.35am the following morning.

The superintendent said it was a tragic event and his thoughts were with the boy's family.

'The family and certain friends will be doing it tough this afternoon as they go through this process,' he said.

The boy's family were notified of his death on Saturday.