Leading article: What a racket

Skulduggery in sport is nothing new. In the ancient funeral games described in Virgil's Aeneid, an athlete slips on a patch of oil that a rival has deliberately spilt on the track. In more recent times, we've had the Olympic fencer who fitted up his weapon so that it registered hits that were no such thing; match-fixing in both football and cricket; drugs in athletics and cycling; and the nobbling of racehorses.

Tennis, however, has remained largely above suspicion. The odd tantrum aside, it's a sport that stands very much at the civilised end of the spectrum, its values enshrined in the quotation from Kipling's "If" at the entrance to the Centre Court at Wimbledon. Splendour in the grass (or on indoor carpet) and handshakes across the net.

How wrong we were. All of a sudden, tennis finds itself at the centre of one of the most bizarre allegations in the history of any sport. A German player, we are told, was poisoned during his country's recent Davis Cup match against Russia. Germany lost, Russia are now in the final, and the authorities are in a state of consternation.

The poisoning claim is merely the latest in a series of convulsions that has gripped tennis in recent weeks. The British star Andy Murray accused unnamed players of throwing matches. A top Russian was fined for not trying hard enough. Martina Hingis, a former Wimbledon champion, tested positive for cocaine and – protesting her innocence – promptly announced her retirement.

Whatever next? Will Wimbledon need to start checking the contents of its lemon barley water? Those who say you cannot be serious might just have to think again.