Los Angeles: R&B star Rihanna has posted a series of topless pictures on Instagram while vacationing in Brazil.
In the racy pics, Rihanna, 25, wears a gold string bikini and in some shots she has discarded the top, reported E! online.
The `Diamonds` hitmaker had also uploaded photographs of herself cavorting in a botanical garden over the last weekend in a revealing one-piece.
Rihanna is currently in the South American state for a Vogue Brazil cover shoot.