British police investigating the disappearance of Madeleine McCann have released two computerized sketches of a man who was seen carrying a child on the night the girl vanished.

The images of the white male, described as between 20 and 40 years old with a medium build and short brown hair, were released to the public on Monday.

McCann vanished on the evening of May 3, 2007 from her family’s holiday apartment at a Portuguese resort, just days before her fourth birthday.

She was sleeping in the apartment with her brother and sister when she disappeared. A window was found open when the girl’s parents, Kate and Gerry, returned from dinner at a nearby restaurant.

The Metropolitan Police say they are now focusing on the man who was seen near the resort around 10 p.m. that night, carrying a child towards the ocean or the town centre.

Police have also released other sketches based on numerous sightings of different males with blonde or fair hair, seen near the scene where McCann vanished. Investigators said they’ve identified 41 people of interest, including 15 U.K. nationals.

In an investigation update issued on Monday, police said there was an increase in burglaries at the resort where the McCanns were vacationing. The burglaries peaked in April 2007, with two of them occurring in the same area where the girl disappeared, police said.

Police are also looking into four separate charity collector sightings in Praia da Luz on May 3.

A detailed reconstruction of the events leading up to McCann’s disappearance will be broadcast in the U.K. on the BBC program “Crimewatch” Monday night. Police hope the re-enactment will jog someone’s memories and lead them to new clues.

Portuguese police dropped the case in 2008. The McCanns hired private investigators to pursue new leads, until Scotland Yard started a fresh investigation into the disappearance in 2011.

British investigators say the timeline of the events leading up to McCann’s disappearance have significantly changed since they took up the case.