The teen entered the church’s Australian headquarters at Chatswood in Sydney’s north on Thursday and allegedly fatally stabbed a 24-year-old man and injured another, aged 30.

It is believe the teen had begged her not to go through with the purification ceremony the night before the incident.

The pair are understood to have fought on Thursday, and he was escorted off the Scientology grounds when he allegedly attacked two male members of the church.

View photos A 16-year-old boy (pictured) entered the facility at Chatswood in Sydney’s north on Thursday and allegedly stabbed a 24-year-old member of Scientology killing him. Source: 7 News More

The deceased, a Taiwanese national, was allegedly stabbed in the neck. It’s understood he was a parishioner studying at the sprawling bush centre.

Detectives say the teenager was asked to leave due to a “domestic incident” and that he allegedly produced a sharp 25-centimetre long kitchen knife while on the driveway.

Police officers arrested the boy after drawing their stun guns as ambulance and fire crews arrived on the scene.

The teenager underwent a mental health assessment at Royal North Shore Hospital on Friday before being taken to Chatswood Police Station.

Detective Chief Inspector Simon Jones on Thursday said the assailant was of “Asian descent”.

News footage showed him being led away by police with his cuffed hands inside evidence bags.

View photos A second Scientology member was injured. NSW Police are pictured here on the scene at Chatswood. Source: AAP More

The Chatswood facility is only for members with a high level of status.

Many come from across the country, along with New Zealand and Asia to attend courses which can cost up to $800 an hour.

Scientology expert Tony Ortega said the incident was “very strange stuff”.

“That is why scientology will not be very forthcoming about what is happening at that place,” Mr Ortega said.

“Scientology will shut this down as quickly as they can.”

One member was also seen preventing a neighbour from speaking with the media.

Scientology released a statement describing the incident on Thursday as “tragic”.

View photos A Scientology spokesman described the incident as ‘tragic’ as police are seen acquiring evidence. Source: AAP More

“We are working closely with the police in relation to this matter and cannot release any further details,” the statement reads.

“We will continue to fully co-operate with the police in relation to their investigation.”

The teen is yet to be charged, but is expected to be accused of murder.

He may also face charges relating to injuries received by the second member, who has since been released from hospital.

It is believed that police have had some trouble contacting the family of the 24-year-old that was killed to tell them of what has happened.