The prestigious Academy has become embroiled in allegations of sexual misconduct by the husband of one of its members and is reeling over the admission that the names of some prize-winners - the subject of intense speculation and on which many people place bets - were leaked in advance.
"The Swedish Academy wants to inform that Sara Stridsberg told the academy on April 27 that she wishes to leave her duties as a member," the committee said in a statement, giving no further details.
Earlier this month, Academy chief Sara Danius stepped down and four other members also announced their withdrawal from the board in the wake of the controversy.
Arcane rules that make appointments for life have so far meant that the 18 members have not been able to technically resign. But Swedish King Carl XVI Gustaf said last week he would change the rules, making it possible to bring in new members.
The crisis enveloping the Nobel literature prize body has sparked speculation in media that the prize could be canceled this year. The committee's selections fascinate and often baffle literature lovers the world over.
The 2016 award to American folk singer and troubadour Bob Dylan sharply divided opinion over whether a popular musician should be given an award that had been largely the domain of novelists and playwrights.
The financial crimes unit of the Swedish police said on Friday it had begun an investigation into the Swedish Academy, but gave no further information.
(Reporting by Helena Soderpalm; Editing by Mark Heinrich)