BARCELONA, Aug 20 (Reuters) - The chief of poilce in Catalonia said on Sunday he could not rule out that the last suspect still believed to be at large in the Barcelona attacks may have crossed to France.

"We don't have any specific information on this but it cannot be ruled out," Josep Lluis Trapero told a news conference in Barcelona, adding that border checks had been reinforced immediately after the attacks.

Trapero also said he could not confirm who was the driver of the van that killed 13 people in Barcelona. (Reporting by Angus Berwick, writing by Julien Toyer; Editing by Adrian Croft)