The singer - whose explicit video for new track `S&M` has been banned in 11 countries - was spotted stocking up on erotic items in Sydney`s notorious adult shop The Tool Shed.
Her assistant was seen leaving the store with two black bags full of mystery purchases, a spokesman for the shop confirmed they had to ensure no other customers were present so Rihanna had a free reign to choose her X-rated products.
He added: "I can`t say what Rihanna did or what she bought - it`s top secret."
Rihanna - who is famous for her flesh-flashing stage outfits and revealing fashion choices - recently claimed girls who attack her for her provocative look are "hypocrites".
She explained: "People think I`m overly sexy. It bothers them for some reason. Girls don`t like to see other girls dressed sexy. It`s a little intimidating, I don`t mean that in a cocky way. There`s always going to be somebody not liking what you do.
"People have a lot of crazy opinions on things. Things I say, things I wear, places I go. It`s just stupid. It`s bulls**t. I`m a young human being. It`s fine for me to go to a club.
"People are hypocrites. They can`t wait to say something horrible. Most of them are unhappy with themselves. It`s women who are mad at other women. They should take a look at their own lives. A lot of people don`t have the guts to confront themselves."