Portuguese authorities searching for missing girl Madeleine McCann have placed a British man under formal investigation in the case, Lusa news agency said Tuesday.
It quoted police as saying the suspect was Robert Murat, 32, who was questioned late Monday along with an unidentified German woman and a Portuguese man as part of the investigation into the disappearance of the four-year-old Briton. Murat was questioned for more than 12 hours. He left the police station in the back of a vehicle early Tuesday but it was not known where he went.
Police did not reveal what led them to place him under investigation and the country's national police chief said the public should remain "very cautious" about developments in the case.
The other two were released without being named formal suspects like Murat. Murat had worked for the police in the inquiry as a translator, and taken a keen interest in the case, according to journalists covering the event.
Investigators on Monday searched Murat's home in Praia da Luz some 100 metres (yards) from the Ocean Club complex where the little girl went missing on May 3 while her parents ate in a nearby restaurant.
Investigators in white forensic suits searched the villa's garden and emptied its swimming pool. They left carrying boxes and plastics bags, which Portuguese media said may contain video cassettes and computer equipment.
The case has sparked a outpouring of sympathy from celebrities, sports stars and the general public in Britain. Rewards totalling more than 2.5 million pounds (four million euros) have been offered for information that leads to the girl's return.
Portuguese newspapers said Murat is divorced, works for a real estate agency and lives with his elderly mother and small son in the villa. They said he also has a four-year-old daughter who lives with his ex-wife in England.
Portuguese national police director Alipio Ribeiro said Tuesday: "The inquiry is evolving but I can guarantee no results." Speaking at a seminar in Lisbon, Ribeiro said "police are doing everything possible" to find the girl.
"We are carrying out systematic searches. We must all remain very cautious." Portugal's attorney general, Fernando Pinto Monteiro, refused to comment on the naming of Murat, apart from saying: "No theory has been discounted. Police are acting very well."
Police had decided to search the house after a tip-off from journalist Lori Campbell, of Britain's Sunday Mirror, who found Murat's behaviour suspicious, according to British media. "Basically he surfaced on Friday afternoon last week and was walking around as if he was somebody official. He claimed that he was just a local guy who spoke fluent Portuguese and English and was helping the family," Campbell said.
"He was coming in and out of the family apartment speaking with the media and acting like he was somebody official. But when questioned about it, he was very vague about his position."