One of Australia's best-known children's charities says its campaign to maintain gun restrictions has prompted pro-gun extremists to abuse its staff.
The Alannah and Madeline Foundation says it has been subjected to threats, abuse and "enormously sickening allegations" about founder Walter Mikac.
Mr Mikac's wife, Nanette, and young daughters, Alannah and Madeline, were among the 35 people killed during the Port Arthur massacre in 1996.
"Our staff, who are used to providing care and support to children, ... at first found it quite overwhelming to be the subject of such abuse," the foundation's chief executive Lesley Podesta told 3AW on Tuesday.
She says the abuse followed the foundation's campaign for the restriction of high-powered guns, such as the Adler A110.
Ms Podesta stressed the abuse came from "extreme elements of the gun lobby" and not the majority of licensed shooters who are "decent and thoughtful".
She also told the Herald Sun on Tuesday the gun industry told disenfranchised, poor men that having a gun would give back their masculinity.
Peter Solomon, who administrates the 30,000-strong 'Australian National Firearms Lobby' Facebook group, says Ms Podesta's suggestion that gun owners are disenfranchised men is wrong.
"To suggest we are young, unemployed and dumb is an absolute insult and low brow in the extreme," he posted to Facebook.