LONDON (Reuters) - Former Wimbledon champion Marion Bartoli is suffering from a virus that forced her withdrawal from an invitational event at the grand slam tournament in London and has her fearing for her life.

Bartoli, who has lost 20 kg since picking up the virus early this year, said on Thursday she could stomach only organic salad and peeled cucumbers.

“I fear for my life, I’m afraid one day my heart will stop,” the 31-year-old, who won the Wimbledon title in 2013, told British ITV’s This Morning program.

"My life is a living nightmare. I don't wish this on anyone but it is gradually getting worse.

“I am wasting away and I don’t know why,” said a gaunt-looking Bartoli of the illness which doctors have no name for. At the French Open in May Bartoli had said she had eating issues but liked her new slim look.

Bartoli said she thought at first her ailment was due to jet lag after taking several flights between Australia, India and New York in January and February.

As the illness has worsened, she has become so sensitive she washes with mineral water and wears gloves to dial numbers on her mobile phone.

Bartoli, withdrawn from the invitational tournament on medical grounds, said she was due to start a course of treatment on Monday.

(Writing by Rex Gowar; editing by Clare Lovell)