More details are expected to emerge about the two men who allegedly helped radicalised Sydney teenager Farhad Jabar kill NSW Police employee Curtis Cheng.
Two men were on Thursday charged in relation to the murder of Mr Cheng, who was shot dead outside police headquarters in Parramatta on October 2.
A 22-year-old man from Merrylands was charged under NSW legislation for the supply of a firearm, breach of a firearms prohibition order and hindering police.
An 18-year-old from Wentworthville, who has been in police custody for the past week, was charged with aiding, abetting, counselling and procuring a terrorist act under section 101 of Commonwealth Criminal Code Act 1995.
The charges relate to supplying the gun Farhad Jabar used to shoot police accountant Curtis Cheng.
"It carries life imprisonment. It is a very serious charge," AFP Commissioner Andrew Colvin said at a press conference.
Two men to face court
Both men have been refused bail and will appear before court on Friday.
The 22-year-old was arrested in Merrylands West at 10.45am today before being taken in for questioning. He will appear before Parramatta Local Court and the 18-year-old is expected to appear at Central Local Court.
On Thursday, NSW Police Force Commissioner Andrew Scipione said the arrests were a "significant development" in the investigation into the shooting.
"You have tenacious police who are determined to get to the bottom of this," said the Commissioner.
"We expect them [both] to be before the courts tomorrow," Commissioner Scipione said. "One at Parramatta, one at Central. The facts will clearly articulate the issues we're having difficulty putting before you."
'We're not going to speculate on linkages'
"This is a very positive and welcome development in what will be a lengthy investigation," AFP Commissioner Andrew Colvin said.
"These charges today are serious charges even if they weren't related to terrorism, but they are.
"What we have seen over the last days and weeks is police using the full array of laws that is available to them in a balanced and appropriate way."
He said the developments should reassure the community that everything is being done to find those responsible for the murder of Curtis Cheng.
“I have said repeatedly our first priority is the safety of the community and today the laying of charges against these two men should reassure the community, that where there is evidence of criminal offending, we will find it and act."
Commissioner Colvin said speculation reported in the media on linkages to people and groups in the Middle East are incorrect.
"As part of the charge, and you will see the facts when they turn up to court. As part of the charge...we don't need to link this to a terrorist organisation," he said.
"We are not going to speculate on motives, we're not going to speculate on linkages [to terrorist organisations]."
The police accountant was shot dead at point blank range by 15-year-old Farhad Jabar outside the Parramatta police headquarters almost two weeks ago.