Image copyright ABC Image caption More than 150 police officers were involved in Friday's raidsMore than 150 Australian police officers have raided three homes after this week's deadly siege in Melbourne.
On Monday, gunman Yacqub Khayre was shot dead at an apartment building after he killed a man, took a woman hostage and wounded three policemen.
A 32-year-old man was arrested on Friday, but police said he was not "of national security interest".
The raids related to how Khayre had obtained weapons before the suspected terrorism incident, authorities said.
Police have said Khayre, 29, made comments referencing so-called Islamic State and al-Qaeda during the siege.
"I want to make perfectly clear, we have not yet uncovered anybody with links to terrorism who are associated with the offender," said Victoria Police Deputy Commissioner Shane Patton.
"They are not persons of national security interest, but they are persons who are known to us through their criminal history."
Image copyright Reuters Image caption Gunman Yacqub Khayre, pictured in 2010, was shot dead by police on MondayMr Patton said authorities were investigating how Khayre obtained a shotgun and a sawn-off shotgun.
Police also seized an imitation firearm on Friday.
The siege victim, 36-year-old Kai Hao, was remembered this week as a loving son who was married only weeks ago.