The scandalous story of Daniel Köllerer, the most hated tennis player in history

Daniel Köllerer's name probably still rings a bell for many tennis fans, not because of his impressive sporting exploits, but because of the controversies that marked the Austrian's career.

Köllerer turned pro in 2002 at the age of 16 and would slowly make his way up the rankings.

In October 2009, he reached a career-high ranking of world No. 55.

That same year, he achieved the best Grand Slam result of his career, advancing to the third round of the US Open, where he lost to eventual champion Juan Martín del Potro (pictured).

Köllerer ended his career without a singles title to his name, but still managed to leave his mark on tennis history.

During his career, he was involved in several controversies that did not make him popular with his tour colleagues.

Köllerer was nicknamed 'Crazy Dani', as he was known for insulting opponents and referees and looking for trouble.

In 2006, his misbehaviour cost him a six-month ban from tennis.

In 2009, the Austrian was struck by a family tragedy when his mother died of cancer, a huge blow for Köllerer.

In 2010, the Austrian showed his worst side when he got involved in a racism incident with Brazilian player Júlio Silva in a match on the ATP Challenger Tour.

Köllerer reportedly called Silva a "monkey" and urged him to "go back to the jungle", and the Brazilian pressed charges after that match.

Another controversial incident involved compatriot Stefan Koubek, who grabbed Köllerer by the throat in the Austrian league.

Köllerer reportedly insulted Koubek during the game, after which the latter lost control. "I'm man enough not to let myself be insulted, especially not by him," Koubek was quoted by the Austrian Times.

"All the players hate him," Koubek also said, according to wearetennis.bnpparibas. "In his mouth, the word "a--hole" is a flower. If spectators could understand his insults, they would break his neck."

Köllerer, however, was not concerned about other people's opinion of him: "I don't care about what others say about me. If I have to change, I will do it for me, not to please others," he is quoted again by wearetennis.bnpparibas as saying.

In 2011, Köllerer suffered a huge blow when he was banned from tennis for life for match-fixing.

In addition, the Tennis Integrity Unit fined him US$100,000, a decision that was later overturned by the court.

Naturally, the lifetime ban meant the end of Köllerer's career, but he is still remembered, albeit less fondly than other players in history.