Ex-Formula One driver Cristiano da Matta is fighting for his life in hospital after a freak accident at Elkhart Lake in testing.
The Brazilian was racing flat-out at speeds of around 180mph in his Champ Car when a deer ran across his path.
Eye witness reports suggest da Matta slammed into the deer head on, with the stricken animal bouncing into his head while his car careered into the barriers at full speed.
The 32-year-old suffered serious head injuries and was airlifted to a Wisconsin hospital where he underwent emergency brain surgery, leaving him in a critical condition.
Champ Car's medical director Chris Pinderski said: 'After arriving at Theda Clark Medical Center, a head CT scan showed Cristiano had suffered a subdural hematoma.
'He was urgently taken to the operating room for surgical removal of the hematoma and is now being observed in the intensive care unit.'
The 2002 Champ Car title winner drove for Toyota for a season and a half between 2003 and 2004, competing in 28 grands prix and scoring 13 points.
Toyota reacted to his accident in a statement from the Hungaroring, venue for this weekend's Hungarian Grand Prix.
It read: 'When he was with Toyota, Cristiano was always a fighter and everyone involved in the team wishes him the best as he fights for his recovery.'
Da Matta's RuSport team have withdrawn his team-mate, Yorkshireman Justin Wilson, from the remainder of the test.
