Crossbench senator David Leyonhjelm has defended using the deadly tragedy on Melbourne’s streets to make a statement about guns.

Three people were killed and at least 20 were injured after a rogue car ploughed into pedestrians in Melbourne’s CBD on Friday afternoon.

The Liberal Democrat, an outspoken supporter of gun owner rights who favours easing restrictions on guns, came under fire for using the incident to suggest it was people, not objects, that killed.

“Probably one of those semi-automatic assault cars,” he tweeted as the disaster unfolded.

Probably one of those semi-automatic assault cars. https://t.co/8oUYMryALl

— David Leyonhjelm (@DavidLeyonhjelm) January 20, 2017

His comment prompted hundreds of angry replies, with many calling on him to resign for making jokes about the disaster as families wait to find out if loved ones have been injured or killed.

.@vanbadham @theheraldsun Please use our official complaints form. pic.twitter.com/piuXLw20KT

— David Leyonhjelm (@DavidLeyonhjelm) January 20, 2017

Senator Leyonhjelm told AAP the outrage “only emanates from those who are too stupid to get it”.

“My comment referred to the ‘rogue’ car, as if the driver is irrelevant,” he told AAP.

“It’s people who commit crimes, not inanimate objects.

“The same argument applies in the debate about firearms.”

Barrister and human rights activist Julian Burnside tweeted: “So ignorant, and in such bad taste. The tragedy is that Leyonhjelm is in our parliament. He disgraces our parliament and himself.”

Former journalist and commentator Mike Carlton said: “Leyonhjelm is a grub. That is all.”

Greens Leader Richard Di Natale has called on Senator Leyonhjelm to apologise.

“This is a tragedy and not the time for crass political point scoring,” Senator Di Natale told AAP.

“Senator Leyonhjelm needs to pull his head in and apologise for his insensitive comments.”