Justin Bieber calls Selena Gomez 'most elegant princess in the world'

Selena Gomez, left, and Justin Bieber arrive at the 39th Annual American Music Awards on Sunday, Nov. 20, 2011 in Los Angeles. (AP / Chris Pizzello)

Justin Bieber has called Selena Gomez the "most elegant princess in the world."

The singer posted a picture of Selena, who is his ex-girlfriend, on his Instagram account following Sunday night's Oscars in Hollywood.

The photo shows her in an Emilio Pucci dress for the Vanity Fair party, with the short "elegent princess" caption written underneath.

Bieber's move sparks speculation he could be trying to win Selena back for a third time.

The couple were first linked in 2010 but split in January 2013, only to get back together again briefly at the beginning of this year.

Gomez has credited their initial split with helping to turn her career around, saying: "I turned 20, went through a really bad breakup, and realized I needed to pick up everything ... I was tired of feeling defeated."

However, once she got back with Bieber, things didn't go smoothly and they soon split again. Gomez then headed to rehab at The Meadows clinic in Arizona and Bieber took model Chantel Jeffries on holiday with him to Panama and Miami.

Bieber, 20, has recently found himself in a number of legal troubles due to his behaviour in the U.S. and his native Canada. His uncle, Brad Bieber, thinks his actions are down to him missing Gomez.

Brad Bieber has said: "How would you feel if your first love didn't work out? How would you feel if that relationship went sour and then it became public and you had no chance to heal or sort out your own emotions and feelings? He is just a brokenhearted, lost little boy."