The "disturbing" final hours of Justin Tsang, the Sydney teen allegedly murdered over $500.

— With AAP. 

On March 15, Sydney teenager Justin Tsang disappeared from his Canada Bay home.

The 17-year-old was reported missing after his family had not seen or heard from him for four days.

Four days later, on March 19, Justin’s body was discovered in a shallow grave at Wentworth Falls in the Blue Mountains.

Now, a week later, three teenagers have been arrested for allegedly kidnapping and murdering the 17-year-old.

Alleged ring leader Yigit Erdogan, 19, and 18 year olds Chris Hopkinson and Joel Robertson faced Burwood Local Court on Thursday, as it was heard that Justin had been “physically assaulted for hours and hours” before he died.

Detectives said Justin pleaded for his life as he was tortured before he was killed.

“You could say it’s torture,” Detective Superintendent Scott Cook told reporters on Thursday.

“There was some suggestion he was pleading for his life. It’s very sad.”

Detectives from the Homicide Squad charge three men over the alleged murder of 17yo Justin Tsang #BurwoodHeights #StrikeForceLieberthttps://t.co/aLLeBlX2VX pic.twitter.com/GY3EeC7B6V

— NSW Police Force (@nswpolice) March 27, 2019

The detective said the motive appeared to be related to a dispute over property.

Court documents suggest Justin was kidnapped and assaulted with the intention of obtaining $500 cash.

“It’s very concerning in a sense that if the underlying motive is a property dispute how can that escalate to torture,” Det Supt Cook said.

“It really is disturbing.”

Detectives on Wednesday searched a Burwood Heights house and arrested four men – including Hopkinson and Robertson.

Two other men were released pending further inquiries.

Erdogan was arrested in Bankstown on Wednesday night and charged. Police allege he organised and coordinated the killing.

They say Erdogan – who was known to Justin – picked him up from a Drummoyne house on March 11 in a BMW sedan.

It's understood he was the only one from the trio that knew Justin.

He was taken to the Burwood Heights house where the other men lived, held against his will and stabbed to death, it's alleged.

It's believed the men who lived in the Burwood Heights house met each other through online gaming.

Hopkinson stood guard with a wrench during the murder, the Burwood court heard.

Hopkinson's lawyer, Ken Buckman, argued his client was afraid and intimidated by Erdogan, who'd allegedly handed him the wrench.

"He was a very scared young man," Mr Buckman said.

Erdogan appeared at Bankstown Local Court on Thursday. He didn't apply for bail and it was formally refused. He's due to reappear on May 23.

Hopkinson and Robertson – who hadn't applied for release – were both refused bail to reappear at Burwood Local Court on May 29.