Palermo, January 21 - The inquiry into the mysterious 2007 disappearance of Sicilian businessmen Antonio Maiorana and his son Stefano evidently made a breakthrough Wednesday as excavations disclosed a shoe and bag stained red that were being examined by police forensic experts, police said. The shoe and the bag were found in a layer of building material in searches that began after the inquiry was re-opened due to new witness evidence. The two vanished after leaving a construction site on the Isola delle Femmine in Palermo province where they were building houses. They said goodbye to the workers and left personal effects in their offices at the site, suggesting they intended to return shortly. Their Smart car was found in a car park at Palermo airport but it emerged that the two men never took a flight from the facility. Since 2007 investigators worked on various theories including a possible Mafia connection or a dispute at their work project and false sightings of the two were reported in Barcelona. The prosecutor's office recommended shelving the case but a judge ordered Carabinieri police to use georadar to search a vast area where Antonio Maiorana's cellphone was tracked to having been a short time before he disappeared. That second probe also was shelved until the investigation was re-opened again less than a year ago due to tips to investigators, judicial sources said.