Police are investigating allegations that junior tennis player Gabriella Taylor was poisoned during her Wimbledon campaign in July.
British teenager Taylor was forced to withdraw from her girls' singles quarter-final match at Wimbledon last month due to a mystery illness.
Taylor, 18, was left in intensive care, with her mother fearing for her life after being diagnosed with leptospirosis - a bacterial disease spread by animals.
"Merton police are investigating an allegation of poisoning with intent to endanger life / cause GBH," Metropolitan Police said in a statement to Omnisport.
"The allegation was received by officers on 5 August with the incident alleged to have taken place at an address in Wimbledon between 1-10 July. The victim was taken ill on 6 July. It is unknown where or when the poison was ingested.
"The victim, an 18 year-old woman, received hospital treatment and is still recovering."
As police investigate the claims, medical experts believe it is highly unlikely Taylor was poisoned.
Dr Marga Goris, who works as an academic at the Leptospirosis Reference Centre in the Netherlands, said: "If you really wanted to poison someone, you would choose another method."