Inspectors from the Office for Standards in Education, Children's Services and Skills (Ofsted) downgraded Darul Hadis Latifiah in Bethnal Green after an inspection during which a book was found in the library which promoted "inappropriate" views on "how girls and women should behave".
The school, which caters for boys aged 11 to 20, said it was unaware of the book's presence and that it referred only to the belief women should "dress modestly", the Evening Standard reports.
Respect for women was taught, but was limited "to the roles of motherhood and families" during Islamic studies, the report noted.
Badrul Islam, secretary to the school's governing board, said, "We are currently preparing a formal complaint to Ofsted about the way the inspection was conducted and judgments were made.
"Nor does it give an accurate picture of the overall quality of teaching, and of parents' views of the school's performance," he said.
Inspections of independently run schools in the UK make it incumbent upon them to make necessary changes or face closure.
Disclaimer: No Business Standard Journalist was involved in creation of this content