Anthony Ervin’s fightback from the depths of despair failed to earn him a medal at the London Games.

The 31-year-old American swimmer has endured a turbulent time since bursting on to the scene by winning the 50m freestyle in 2000.

After falling out of love with the sport following his success, he auctioned off his Olympic gold medal to raise funds for tsunami victims and moved to New York to join a rock band.

In a recent interview, he told Rolling Stone Magazine: “When I gave it all up, I went into my chrysalis and did all my partying and self-actualising in New York. I’d like to think that I’m emerging now as my moth. And I’m going to fly into the flames.”

Ervin, whose mother is Jewish and father African American, lost his way after Athens and admitted to becoming involved in drink and drugs before fighting his way back to competition.

Diagnosed with tourettes at a young age, Ervin had a difficult childhood with swimming providing his only real outlet for his problems.

At the age of two, his mother built an iron-fence around the family swimming pool after Ervin had managed to slip his parents’ attention and run towards the water. That fence came to symbolise a barrier and one that he would strive to overcome during a troubled childhood.

And his gold medal winning performance in Athens looked to have helped him turn the corner only for college life to send him off the rails once more.

But following a battle with depression in 2010, he returned to coach kids in New York and was persuaded to begin competing again. Sadly, he only managed fifth place in London.

“Being here is my own form of redemption,” Ervin said. “What’s next? I’m going to have a nice dinner with my friends and family, people I really care about. Without them, this could not have happened.”