Roman Polanski was ejected from the Academy along with disgraced comedian Bill Cosby in 2018.
Now the polish born film director of Chinatown is suing the Academy after being kicked out of the Oscars organisation.
A lawyer for the long-time fugitive filmmaker said that he was expelled "without warning" and with no chance to respond.
Polanski's lawyer filed a writ at the Los Angeles Superior Court and will pursue legal action against the film institution on grounds that the famed director's expulsion was unfair.
But the Academy responded hours later and said in a statement its removal of Polanski from its ranks was "fair and reasonable" and it will not reverse the decision.
It said in a statement, "The procedures taken to expel Mr Polanski were fair and reasonable. The Academy stands behind its decision as appropriate.", reports Variety.
Polanski, who has been on the run for decades following a sexual abuse case, was told of his ejection in a letter citing the need to respect "human dignity".
Representing the long-time Academy member, lawyer Harland Braun has also written to the Oscars overseers on behalf of Polanski.
Documents say the intention of legal action is to "redress the Academy's improper administrative action" to "summarily expel" Polanski.
Braun told the Press Association: "If you notice, we are litigating the fairness of their procedure.
"They threw him out without warning and without giving him a chance to respond. There was not even any notice of why, after 40 years, on the same day as Cosby.
Polanski was voted out of the Academy in May of 2018, receiving an unsigned letter from the organisation.
The director has been a fugitive from US justice since 1978, following accusations of a sexual offence.
A letter, made available by to the court, cites the need to uphold respect for "human dignity" as the motivation for the action taken in 2018.
It states: "The board continues to encourage ethical standards that require members to uphold the Academy's values of respect and human dignity, and is categorically opposed to any form of abuse and harassment."
Braun claims in his writ that: "The Academy failed to comply with its own rules, polices, and regulations" when it ejected Polanski.
The director fled to France in 1978 after being arrested and charged with the rape of a 13-year-old girl in the US.