Danny Cipriani was reportedly arrested on suspicion of drink-driving at 5am on Monday, hours after starring for England.
Cipriani scored 33 points in England's thrashing of the Barbarians at Twickenham, winning the Man of the Match award, hours before the incident took place in Chelsea, west London.
The Sale Sharks star's Mercedes was involved in a collision with another car at about 05:15 BST.
Cipriani was not hurt in the incident but was breathalysed at the scene and then taken to a police station in Fulham where he was released on bail.
"The cars involved were a silver Toyota Prius and a black Mercedes C63," said a Met Police spokeswoman to the BBC.
"The driver of the Mercedes, a 27-year-old man, was arrested on suspicion of drink-driving.
"He was taken to a west London police station where he was later released on police bail. Return date to be confirmed."
The news comes at a time where England have already lost Manu Tuilagi and Dylan Hartley from their World Cup squad due to either on-field or off-field disciplinary issues.
England head coach Stuart Lancaster will be monumentally frustrated with Cipriani given his fine performance at Twickenham only hours before his arrest.
He had battled his way back into contention to make England's Rugby World Cup squad but based on way the cases of Tuilagi and Hartley have been handled, his place in the 50-man training group has to be in doubt.