Portuguese police said today they believe missing three-year-old British girl Madeleine McCann has been abducted.
Guilhermino Encarnacao, director of the judicial police in the Faro region, said detectives have a suspect in mind but refused to reveal any details for fear of endangering Madeleine's life.
He said police were hopeful she was still alive and believe she is still in Portugal.
Streets and lanes through the beach side complex were sealed off as members of the Portuguese National Republican Guard watched over the apartment where the Leicestershire toddler went missing on Thursday night.
Last night, his voice cracking with emotion, Madeleine's father Gerry, a doctor, issued a personal appeal to anyone holding his daughter captive to release her.
In an appeal to the public for help in tracing Madeleine, he also said: "Please, if you have Madeleine, let her come home to her mummy, daddy, brother and sister."
Madeleine's parents, from Rothley, Leicestershire, returned to their rented holiday apartment on Thursday night after dining at a tapas restaurant just a short distance away to discover the their daughter missing.
Staff and guests joined the desperate search of the complex well into the early hours of yesterday morning while Portuguese border police, Spanish police and airports were also alerted.
Last night police with miner-style headlamps scoured the complex overlooking swimming pools and tennis courts as the search continued.
Speaking for the family, Madeleine's father said: "We can't describe the anguish and despair we are feeling as parents of our beautiful daughter Madeleine.
"We request that anyone with any information related to Madeleine's disappearance — no matter how trivial — contact the Portuguese police and help us get her back safely.
"Please, if you have Madeleine, let her come home to her mummy, daddy, brother and sister.
"Everyone can understand how distressing the current situation is.
"We ask that our privacy is respected to allow us to continue assisting the police in their investigation."
PA