Two charged over Sydney terror shooting

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.

An 18-year-old man from Wentworthville has been charged with a Commonwealth terrorism offence and is due to appear at Central Local Court on Friday.

His 16-year-old brother was in the same grade as the 15-year-old killer at Arthur Phillip High School.

A second man, 22, has also been charged with supplying the gun that Jabar used to kill Mr Cheng, breaching a firearms prohibition order and hindering police.

He was refused bail to appear at Parramatta Local Court on Friday.