After being clocked driving at speeds up to 145 mph in rush-hour traffic, the Brazilian has been fined and suspended from driving for a year.
A court heard how the 29-year-old, who was signed from Turkish side Fenerbahce last summer, failed to stop when pursued by police and switched between lanes on a busy motorway on Aug. 17. The Brazilian eventually pulled his Maserati up close to Arsenal's training ground after speeding on the A1 and M25 in Hertfordshire.
Santos pleaded guilty to driving without due care and attention at a hearing at Hendon Magistrates' Court, and has been handed a 4,500 euro fine by the court in addition to the driving ban.
Santos has only made two appearances for Arsenal so far this season, one in the Premier League and one in the League Cup, with Kieran Gibbs impressing in the left back role.