Police were questioning a man and a woman yesterday over the attempted murder of a detective who was run down as she tried to arrest a fraud suspect, police said.
Detective Constable Catherine Corbett, 39, of West Midlands Police, suffered serious head injuries in the collision near Heathrow Airport on Friday.
In a statement, Scotland Yard said a 41-year-old man and a woman aged 32 remained in custody after being arrested on suspicion of attempted murder on Friday.
Corbett was run over as she tried to arrest a man outside a hotel. She underwent surgery at Charing Cross Hospital, where her family are at her bedside.
Corbett, a single woman from Solihull, was hit by a car outside the Sheraton Skyline Hotel in Hayes. Two male officers were carried along on the car's bonnet before being thrown off. They suffered minor injuries.
The suspect fled in a blue Peugeot 207 that was found abandoned nearby.
"Our thoughts and prayers are with Cathy and her family," a West Midlands Police spokeswoman said. "We are anxiously awaiting news from the hospital."
Corbett was in plain clothes when she was hit. She was in London with a team of investigators who had sought a suspect in a fraud inquiry for 12 months.
She has served with the West Midlands force for 18 years and is part of its Economic Crime Unit
.