One of four men accused of conspiring over the murder of Sydney police accountant Curtis Cheng has raised his index finger in court, in a gesture similar to a salute used by Islamic State militants.
Talal Alameddine, 23, Mustafa Dirani, 22, Milad Atai, 20, and Raban Alou, 18, were already in custody over other alleged offences when charged on Wednesday with doing an act in preparation of a terrorist act.
Appearing via videolink, Atai, who is also accused of helping 15-year-old gunman Farhad Jabar's sister travel to Syria in the day before the killing, lifted a finger as his matter came to a close in Goulburn Local Court on Thursday.
A similar gesture features in pictures of Islamic State militants, including some holding severed heads.
In court documents, police allege Atai has been a member of Islamic State and provided resources to the organisation.
He and the other men are accused of acting in concert with Jabar before the October shooting of Mr Cheng outside police headquarters in Parramatta.
Police say they may have come together on the day of or before the attack, which led to Jabar being killed in an exchange of gunfire with police.
Alou is accused of directing a terrorist organisation and allegedly gave the murder weapon - a .38 calibre Smith and Wesson - to the teen.
Alameddine and Dirani were also involved in supplying the pistol, police allege.
Atai had not been charged with offences relating to Mr Cheng before Wednesday, while the other three have been in custody on a string of charges relating to the father-of-two's death.
The trio had been slated to stand trial mid this year but prosecutors previously asked to have the date vacated, saying they required more time to work on the complex case.
Around 2000 intercepts, including many in foreign languages, need to be transcribed before trial, a court has previously heard.
All the men, except for Alameddine, appeared via videolink but spoke only to answer administrative questions asked by registrar Bernadette Hilton.
Alameddine was the only one to have a representative in court.
The men did not apply for bail and had their matters adjourned to Central Local Court in June.
