A judge is to begin examining police files about the disappearance of four-year-old Madeleine McCann.
Gerry McCann has described events as "an unending nightmare"
He has 10 days to consider the 1,000-page dossier and review evidence involving Madeleine's parents, who were named as suspects last week.
Kate and Gerry McCann deny involvement in their daughter's disappearance.
Portugal's attorney general said the police operation had not ended and indicated bail conditions could be imposed on the suspects.
BBC reporter Caroline Hawley said the options available to the judge included ordering more search warrants and changing the McCanns' "arguido" - official suspect - status.
It had been thought the prosecutor would take longer to study the files, our correspondent said.
On Monday, police gave their files to the Algarve-based prosecutor, Jose Cunha de Magalhaes e Meneses, for him to decide how to proceed with the case.
But just one day later, he passed them on to the criminal instructional judge.
It is unclear why Mr Cunha de Magalhaes e Meneses acted so swiftly.
Possible reasons are that he is recommending charging Madeleine's parents or, considered more likely, that he is requesting search warrants, more interviews or for stricter bail conditions to be imposed.
Madeleine's aunt, Philomena McCann, said the handing over of the files to the judge "was expected".
"It doesn't change a thing," she said. "We will have to wait and see if they are bringing charges or not.
"If they bring charges against Kate and Gerry that will give them a chance to clear their name."
The Home Secretary, Jacqui Smith, told the BBC she wanted to see an end to the media speculation over the case.
"When the Portuguese have asked for support from British police or expertise we've provided that.
"But what I also think is that actually at the moment there's a lot of unhelpful speculation around the progress being made in this case and I certainly don't want to add to it."
Portugal's Attorney General, Fernando Jose Pinto Monteiro, said that the investigation had not ended.
He said that further police action was necessary after which there could be a reassessment of possible bail conditions for the suspects.
He had full confidence in the way the police and prosecutors were handling the McCann investigation, he said.
Madeleine McCann's fourth birthday was just after she went missing
A district prosecutor - Luis Bilro Verao - has also been appointed to oversee the investigation in addition to the local prosecutor in charge.
The BBC's Richard Bilton said the forensic case centred on the McCanns' hire car, leased more than three weeks after Madeleine was last seen.
The car was searched by sniffer dogs in early August and the McCanns' family said detectives had put it to Mrs McCann that her daughter's blood had been found inside.
But Portuguese police have played down reports that DNA evidence with a 100% match to Madeleine was found in the car.
The McCanns, both 39, returned to their home in Rothley in Leicestershire on Sunday.
No bail conditions have been imposed on the couple, but they can be recalled to Portugal with five days' notice.
Mr McCann described the events of the past week as an "unending nightmare".
In his blog, he said he and his wife had absolute confidence that when all the facts were presented they would be able to show that "we played no part in Madeleine's abduction".
Madeleine, who was three at the time she disappeared, was reported missing from the McCanns' apartment in Praia da Luz, in the Algarve, on 3 May.