Madeleine McCann disappeared Thursday night from an apartment she and her parents were using on vacation in the Algarve village of Praia da Luz.
Police released an artist's impression of the suspect Saturday and said they remain hopeful that the three-year-old girl is alive and unharmed, the London-based Telegraph reported.
Police, who did not release a name for the suspect, disclosed no other information for fear of endangering Madeleine's life, the Telegraph said.
The girl's parents, Gerald and Kate McCann, were dining at a restaurant 50 yards away when the kidnapping occurred. The couple's two-year-old twins were not taken.
The McCann's made an emotional appeal to the kidnapper to return their daughter unharmed.
"Words cannot describe the desperation and despair we are feeling as parents of our beautiful daughter Madeleine," Gerald McCann said.