A senior Portuguese police officer said detectives investigating Madeleine McCann’s disappearance had a “positive feeling” about the inquiry as they await key DNA test results.
Chief Inspector Olegario Sousa’s comments come amid reports Madeleine’s parents have been told not to leave Portugal amid hopes of a breakthrough.
Police will step up the hunt for the young girl this week by launching fresh searches, according to unconfirmed reports.
Mr Sousa, spokesman for Portugal’s investigative Policia Judiciaria (PJ), said: “We have already said that all the lines are still open.
“Even our director (PJ head Alipio Ribeiro) said that we haven’t enough information to make the picture of what happened that night.
“But we are with a positive feeling on this.”
It was widely reported today that the McCann’s, from Rothley, Leicestershire, had been told it would be bad timing to leave Portugal with important developments expected.
The couple are not suspects and it was believed they were making plans to leave Praia da Luz and return home in the middle of next month.
British detectives and sniffer dogs sent to Portugal to help with the inquiry discovered the blood stains in the McCanns’ flat three weeks ago.
DNA tests have revealed the blood probably came from a man from north-eastern Europe, The Times reported last week.
But a spokesman for the Forensic Science Service (FSS) in Birmingham, which is carrying out the analysis, said that experts were “continuing to examine” the samples taken from the apartment.
Neither Mr Sousa nor the FSS could confirm when the tests would be completed.
Pressed to say whether the picture of what happened on the night Madeleine vanished was becoming clearer, Mr Sousa answered: “Yes, you might say so.
“But we are not with all the information at the moment - we are putting together information.”
Asked about reports this week that the police investigation was now at a “decisive phase”, he said: “A criminal investigation is not made from small things.
“It is made from a lot of things together that will give us a basis to go on. Let’s wait and see.”
Yesterday a friend of Madeleine’s parents hit back at smears about him printed in Portuguese newspapers.
Dr Russell O’Brien, 36, was among the group Liverpool-born Kate and husband Gerry McCann were dining with on the night the young girl went missing from her bed in the Algarve resort of Praia da Luz.
In recent days, Portuguese newspapers have printed allegations about him.
Although it did not name the doctor, one paper included enough details to identify him clearly.
In a statement, Dr O’Brien and his wife, Jane Tanner, said: “These reports in the Portuguese press are completely untrue and extremely hurtful.
“We have spoken to the police, and have been assured that our status as witnesses has not changed.
“We would like to request that the privacy of our family and our police testimony are respected by the media.
“We just hope that the police’s considerable efforts to find Madeleine are successful.”
Portuguese police said there was “no basis” for the allegations about Dr O’Brien, who moved to Exeter from Leicester shortly before the holiday in Praia da Luz.
On the night Madeleine disappeared, he left the table at around the time she is believed to have been snatched.
But it is understood he was looking after his young daughter, who was vomiting at the time.