The footage shows a police officer speaking to the man on his front step for about a minute before he steps forward and strikes the man to the face.
The officer is then seen shoving the man back inside the unit and slamming the front door behind him.
The man comes back out and the officer is seen giving the man another shove to the chest before motioning with his hand for him to go back inside the unit.
Ms Scott said it was her brother’s birthday and he was alone at the unit playing music.
“There were a few words said but [the officer] shouldn’t have done what he’s done,” she said.
“My brother didn’t deserve that.
“He’s in a wheelchair, he’s disabled — he’s defenceless.”
Ms Scott said her brother had struggled with addiction and was never going to walk again.
A Victoria Police spokesperson confirmed an investigation had been launched.
“Victoria Police has been made aware of an incident involving a police officer and a member of the public at a Shepparton address on February 28,” the spokesperson said.
“Professional Standards Command has launched an investigation into the matter after reviewing video and body-worn camera footage.
“The male sergeant in the video has been identified and transferred to other duties while the investigation is carried out.
“As the investigation is ongoing, no further details can be provided at this point in time.”
