LISBON A three-year-old British girl may have been kidnapped from her bed in a Portuguese beach resort while her parents dined nearby, family friends and a police source said on Friday.
"We are investigating," a police source said. "But as time goes by the other possibilities (than kidnapping) are starting to lose importance."
Madeleine McCann's parents, who were on holiday in the Algarve with friends, made an emotional appeal late on Friday for their daughter to be let go by whoever might be holding her.
Authorities had talked to the parents on Friday after Madeleine's disappearance on Thursday night from a holiday villa, the source said.
The parents had put her to bed and were dining 50 metres (yards) away with friends when she vanished from the apartment where they were staying. She was with her twin siblings, who were asleep when the parents returned and found her missing.
Police were joined by sniffer dogs and local rescue services had provided boats and a helicopter to search the resort village with a population of about 1,000.
Jill Renwick, a friend on holiday with the family, told BBC television she was sure Madeleine had been abducted, noting she "couldn't have gone out on her own and the shutters were forced open".
Britain's ambassador to Portugal travelled to the Algarve to help the family. He was confident of strong cooperation in the case between British and Portuguese police, an embassy spokeswoman said.
Portuguese television showed images of white-painted villas in the resort village and the McCann's villa cordoned off.
Renwick said the girl was "very blonde - she's not a likely child to be with a Portuguese family - or is she with other holiday makers?"
(Additional reporting by Tim Castle in London and Elisabete Tavares)