Portuguese police announced Friday they are searching for a suspect in connection with the disappearance of Madeleine McCann, the 4-year-old British girl who vanished during a vacation in Portugal three weeks ago.

Chief investigating police officer Olegario Sousa said at a news conference that police are looking for a white man, between the ages of 35 and 40, who was wearing a dark jacket and beige trousers and who was possibly carrying a little girl on May 3, the date Madeleine disappeared.

"The man was carrying a child or an object that could have been taken as a child" Sousa told journalists. He also said the man was 5 foot, 10 inches tall.

Madeleine disappeared May 3 after her parents left her and her brother and sister, 2-year-old twins, alone in their room while they went to a restaurant inside their hotel complex in Portugal's Algarve region.

Sousa urged anyone who might have seen the man to come forward and said police interviewed witnesses Thursday and Wednesday.

He said dozens of reports of Madeleine's possible whereabouts were still being checked but none had proved positive.

Sousa also said that Interpol has supplied information to the investigation and much information was coming in from sources abroad.

Earlier on Friday, the parents of Madeleine said that the guilt they feel over leaving her alone in a hotel room will haunt them forever.

Gerry and Kate McCann, in an interview with Britain's Sky TV, also said they had no plans to return to Britain without her.

"I can't think about going home without Madeleine," said Kate McCann while holding a pink stuffed toy cat that had belonged to her daughter.