Former world number one Justine Henin has announced her retirement from tennis for a second time due to a persistent elbow injury.

Justine Henin Factfile

The Belgian seven-time Grand Slam champion first retired from the game in the early part of the 2008 season, but made a return to the WTA Tour in early 2010, reaching the final of the Australian Open in only her second tournament back.

The 28-year-old injured her right elbow at Wimbledon last year and did not return to action until this month's Hopman Cup, where she won all her matches, but she lost in the third round at the Australian Open to Svetlana Kuznetsova.

Henin wrote in a letter on her website, www.justine-henin.be: ""After my loss at Wimbledon in June, I knew it would be difficult to come back. But I had decided to keep playing and to give everything to overcome the injury.

"In these recent months, I have rarely been spared from the pain, those last months were very hard. Time has passed, and the doubts have grown, and only returning to the courts would give me answers.

"Not the answer I was hoping for... unfortunately. I suffered a lot the last week and every day gave me more and more pain, but I believed that my will would take the upper hand.

"Today, the examinations are clear and the doctors formally said my elbow is too fragile and hurt, so that my passion and my professionalism at a high level cannot continue to exist."