The Guarda Nacional Republicana (GNR) will carry out from today and until Sunday, an inspection operation focused on heavy goods and passengers vehicles.
Christian Post, 54, believes Christian Brueckner (pictured) snatched Madeleine during one of his burgling night crawls while she slept in the Portuguese resort Praia da Luz.
Christian Brueckner, who is currently in jail in Germany for the rape of an American pensioner in Portugal in 2005, has requested a prison transfer because other inmates want to kill him.
Detectives are said to be frustrated by the failure to compile sufficient evidence to prosecute Christian Brueckner, a convicted paedophile named two years ago by German police as prime suspect.