The woman, born in 1963, told police that she had accepted a lift in an unlicensed taxi.
“After a while she found herself in an apartment where there were a number of men present. It is also in this apartment that she claims to have been raped,” police spokesman Johan Allard told news agency TT.
According to police, there are reported to have been four or five men in the apartment.
Following her ordeal the woman was taken to a rape crisis centre at Stockholm South General Hospital (Södersjukhuset) where the extent of her injuries is not yet known.