The One Nation leader, Pauline Hanson, told a rally in support of Ben Roberts-Smith that the former soldier accused of war crimes is a person “I respect and I admire”, before its organiser called for “an army of civilians” to support him.

About 100 supporters gathered in Rocks Riverside Park in Seventeen Mile Rocks in southern Brisbane on Sunday.

One bore a sign calling for him to be elected prime minister, while others simply carried the Australian flag, or wore T-shirts calling for “justice for Ben”.

Hanson told the crowd that the former Special Air Service Regiment soldier – who was arrested and charged with war crimes in April – was a “war hero”.

The Victoria Cross recipient faces five charges of war crime murder over allegations he killed unarmed civilians during his service with the Australian SAS in Afghanistan. He has categorically denied all of the allegations.

“I think that we see Ben as one of our own. When we see what’s happened to him, you basically sort of think, well, what’s next?” Hanson said.

“Is this the country that I grew up in? Is this the country I want to hand on to my children and grandchildren?”

The senator compared Roberts-Smith’s prosecution to her 2003 jailing for electoral fraud. Her conviction was later overturned and she was acquitted.

“These men and women are trained to fight, and a lot of the time to fight for their life,” she said. “We don’t wear those shoes … the decisions they make at that time, we can’t judge them, and I’m not even going to start.”

Sunday’s event was advertised as a community barbecue for “friends of Ben”.

Organiser Lawrence Henzell started printing and selling shirts bearing messages of support for the former soldier after Roberts-Smith’s April arrest. He said profits from sales went to a trust set up in the former soldier’s name.

“I think right now we need to form an army of civilians and support this man,” he told the gathering.

Henzell later told media that he intends to organise more events for the former soldier.

Some supporters travelled hundreds of kilometres to show their support.

Tammy Hickey rode more than 12 hours on a bus to attend the event on Saturday, travelling from her home in Cunnamulla, western Queensland. She works for the Cunnamulla Aboriginal Corporation as a community development organiser.

“It was very important to support Ben because it’s just a travesty what he’s been put through,” Hickey said. “My father fought in World War Two and he’d be horrified at what Ben’s being put through.”

She said she wanted to have Robert-Smith’s back.

“War’s war. My dad always said that war is war.”