Spaniard Borja Etchart is the latest professional golfer to get disqualified; he was ejected from the Andalucia Open after twice wrongly placing his ball.

A look at the top 10 disqualifications in sports: 

Ben Johnson (Canada, athletics)

Johnson's disqualification following his positive drugs test after winning the 1988 Seoul Olympic 100 metres final in world record time is the biggest doping scandal in Olympic history and dealt a body blow to a sport which is still struggling for credibility.

Linford Christie, who was promoted to second place behind Carl Lewis, won the 1992 Olympic 100 title but tested positive for steroids seven years later.

Justin Gatlin, the 2004 Olympic champion, is currently suspended for doping.

Hansie Cronje (South Africa, cricket)

The late South Africa captain was a born-again Christian and outwardly a model of upright rectitude.

In reality he had a self-confessed "love of money" which led to his life ban in 2000 for accepting bribes from bookmakers and match-fixing.

Two other international captains, Pakistan's Salim Malik and India's Mohammad Azharuddin also received life bans.

Chicago White Sox (U.S., baseball)

Eight members of the Chicago White Sox were suspended after they were found guilty of accepting money to throw the 1919 world series, won 5-3 by the Cincinnati Reds.

Boris Onischenko (Soviet Union, modern pentathlon)

Onischenko, an army officer from Ukraine who had won a silver medal at the 1972 Olympics, left the 1976 Montreal Games in disgrace after it was discovered that he had wired his epee in the fencing competition so that he could trigger the electronic scoring system with his hand to register a hit.

Mike Tyson (U.S., boxing)

Tyson, whose life was fast unravelling following a prison sentence for rape, was disqualified for biting a chunk out of Evander Holyfield's right ear during their 1997 world heavyweight title rematch.

Roberto Rojas (Chile, soccer)

Late in a 1990 World Cup qualifying match, Chile were trailing Brazil 1-0 and facing elimination.

Then Chile goalkeeper Rojas fell to the pitch with an apparent injury to his forehead close to a firecracker which had been thrown on to the pitch by a Brazilian supporter and the match was abandoned.

Floyd Landis (U.S., cyclist)

Landis won the 2006 Tour de France after an epic performance in the 17th stage.

A doping test revealed elevated levels of the male sex hormone testosterone and Landis was stripped of the title and later banned from the sport for two years.