Britney Spears has chained up Nicole Richie at one of her Las Vegas shows.

The singer held Nicole by a leash as she sang Freak Show during her Piece Of Me show at the Planet Hollywood Resort.

Nicole, who was dressed in a dominatrix-style leather outfit, later crawled across the stage and danced after being untied by Britney, reports Digital Spy.

After the performance, Britney presented Nicole with her very own Britney T-shirt.

Later on Twitter, Britney wrote: "Can we all give a round of applause to @NicoleRichie for playing along in the show tonight? U looked hot crawling on all fours ;)."

Other guest stars who've taken part in the raunchy stage show include Mario Lopez and Britney's boyfriend David Lucado.