The film academy said Thursday that its board of governors met Tuesday night and voted on their status in accordance with their Standards of Conduct.
Only one person is thought to have been previously expelled from the academy: Carmine Caridi, a character actor who had his membership revoked in 2004 for lending DVD screeners of films in contention for Oscars that ended up online.
Polanski remains a fugitive after fleeing the United States in 1978 after pleading guilty to unlawful sex with a minor. Cosby was convicted last week of sexual assault in Pennsylvania.