'Mother of Satan' chemicals found: court

Chemicals capable of making an explosive nicknamed "Mother of Satan" were allegedly found in the possession of four men accused of plotting a Christmas Day terror attack in Melbourne, a court has been told.

Federal police chemicals expert Vincent Otieno-Alego analysed substances that could produce up to 2g of triacetone triperoxide (TATP), he told Melbourne Magistrates Court on Tuesday.

Hamza Abbas, 22, his 23-year-old brother Ibrahim Abbas, Ahmed Mohamed, 24, and 26-year-old Abdullah Chaarani appeared in court for the second day of a pre-trial committal hearing.

Each man is charged with planning to use an improvised explosive device and other weapons to target Flinders Street Station, Federation Square and St Paul's Cathedral on Christmas Day 2016.

Dr Otieno-Alego described TATP as "very volatile" and confirmed it was often referred to as "Mother of Satan".

Items found in a red Tupperware container, linked to the case, were also capable of making an explosive, AFP weapons expert Bruce Schiefelbein told the court.

However, he added that individually the items - including a AAA battery, broken light globes and what looked like galvanised pipe - also had "legitimate" uses.

The court has been told previously that the men, who were arrested during raids by the Joint Counter Terrorism Team in Melbourne's north on December 22, were allegedly found with a mixture made of sparklers and match heads.

The hearing continues.