Steffensen, who won a 4x400 metres relay silver at the 2004 Athens Games, said he had been a victim of racism and threatened to pull out of London after being overlooked for selection in the individual event in favour of teenager Steve Solomon.
Steffensen was later given a reserve spot for the individual 400, but Solomon competed in the event at London where he finished eighth after qualifying for the final.
Days before the Games opening ceremony, Steffensen told Australian media he had been racially vilified by an AA official when he competed at the 2008 Beijing Games and booted out of his athlete's accommodation.
An independent legal adviser would be appointed by AA to look into Steffensen's allegations, local media reported on Wednesday.
The 30-year-old athlete, who has South African heritage but was born in Australia, has previously clashed with AA officialdom and boycotted the 2010 Commonwealth Games, alleging mismanagement at the governing body.
Athletics Australia was buffeted by a number of selection controversies in the lead-up to the Games, prompting the Australian Olympic Committee to intervene.
Australia's athletes were set an ambitious target of six medals in London, but came home with only one gold and two silvers.
A review of the team's disappointing London performance, which included Beijing Olympic pole vault champion Steve Hooker flopping in the final, resulted in Eric Hollingsworth losing his job as AA's high performance director.
AA will pick a new high performance director in coming months, with Hollingsworth to be retained as head coach, the governing body said.