"The search warrants that were executed on the other premises were to provide evidence in relation to the activities of the 23-year-old man that was arrested," Mr Gaughan said.
"There is no allegation at this stage that they were involved in any criminality." The arrested man has no family relationship to the man who he allegedly funded to fight in Syria, and they met via social media.
"This is the first time in a terrorism environment that we're aware that an Australian citizen has sponsored, or paid for, a citizen of another country to go into Syria or Iraq to fight," Mr Gaughan said.
Homes across five Melbourne suburbs were targeted in Australia's latest counter-terrorism raids.
One man was taken into custody during the raids in Seabrook, Kealba, Meadow Heights, Broadmeadows and Flemington early today.
Police said the raids were not related to last week's fatal police shooting of Melbourne terror suspect Numan Haider and are not in response to a specific threat to the public.
The man taken into custody early today was at a home in Seabrook.
The Melbourne raids come about two weeks after larger operations were carried out in Sydney and Brisbane.
"The Australian Federal Police and Victoria Police Joint Counter Terrorism Team can confirm that a number of search warrants are being conducted as part of an operation in the following suburbs - Seabrook, Kealba, Meadow Heights, Broadmeadows and Flemington," the AFP said in a statement.
"This operational activity is not in response to a threat to public safety nor is it related to last week's incident at Endeavour Hills.
"While this activity is continuing no further comment will be made."
Teenage terror suspect Haider, 18, was shot dead after stabbing two police officers outside Endeavour Hills police station on September 23.
Haider was under surveillance and the stabbings and fatal shooting occurred after he agreed to meet AFP and Victoria Police officers in the police station car park.
The investigation into the Haider incident includes whether he was acting alone, but police have said it is not their theory that there was a conspiracy to ambush the officers.
Victorian Premier Denis Napthine said he was briefed by police as Tuesday's raids started and was told they were part of a long-running and ongoing counter-terrorism operation.
"They are not about a specific threat or there is certainly no immediate concern for public safety," Dr Napthine told Fairfax Radio.
The premier also urged the community to be tolerant and come together at this time, and said law enforcement was "ahead of the game" in combating the risk of terrorism.
"It's a sad situation that we now face, but we can have confidence in the work of ASIO, the Australian Federal Police and the VicPol. They do a terrific job," Dr Napthine said.
- AAP