British professional boxer Amir Kahn has taken to Twitter to lend his support to Bolton Wanderers midfielder Fabrice Muamba, who has announced his retirement from professional football.

Muamba, 24, has retired from the game following advice from leading cardiologists, and Khan has expressed his sadness at the news.

"Sad to hear Fabrice Muamba has had to retire. I wish him all the best for the future and know it holds great things for him!" Khan tweeted.

Muamba suffered a cardiac arrest in March.