Court says publication on its website was "inadvertent" and that a final ruling has not been made.
The US Supreme Court accidentally leaked a major opinion on abortion rights, appearing ready to overturn part of Idaho's near-total ban.
According to a document published on the court's website then quickly removed, justices will rule that Idaho cannot deny emergency abortions to women whose health is in danger.
The court said the opinion, initially obtained by Bloomberg, was "inadvertently and briefly" published, and that its final decision had "not been released" but would be presented in due course.
Its publication however comes two years after the leaking of the court's decision to overturn the national right to abortion access, known as Roe v Wade.