By Sam Dean and Nazrin Wilkinson, at Wimbledon.

A British teenager who was forced to retire from Wimbledon through illness was on Sunday night in intensive care as doctors tried to diagnose a mystery virus.

Gabriella Taylor was the last British player left in the junior singles when she pulled out of Thursday’s girls’ quarter-final with the score at 4-6, 1-1.

The 18-year-old had been sick since Tuesday night and played through the pain in an impressive third-round victory, but her condition deteriorated on the morning of her quarter-final, where she was visibly unwell.

It was initially believed that Taylor was suffering from food poisoning, but her coach said after her withdrawal that they believed it to be a virus instead.

Her condition has dramatically worsened since then and she has now been placed in isolation in Southampton General Hospital’s intensive care unit.