The Portuguese authorities revealed yesterday that the country's Policia Judiciaria (PJ) have completed their final report into the disappearance of Madeleine McCann, who vanished from the flat in a holiday village on the Algarve where her parents were staying with seven friends in May 2007. A state prosecutor must now decide whether to press charges or declare the 14-month investigation closed.

The feared abduction from Praia da Luz of the three-year-old, who was a few days from celebrating her fourth birthday, became a global news event as reported sightings from Morocco to Switzerland were passed to police. Over a period of six months, attention slowly switched from the hunt for a kidnapper to Madeleine's parents, Kate and Gerry McCann. The couple, both doctors, were declared "arguidos", or formal suspects, on 7 September 2007.

Will Kate and Gerry McCann be cleared?

Luis Bilro Verão, the lead prosecutor, has three courses of action open to him once he finishes examining the evidence, which runs to "dozens of volumes". He can order the PJ to continue their investigation, he can file charges against the McCanns, or he can order the case to be "archived", meaning it will lie on file but all active inquiries will be at an end.

After numerous previous consultations between detectives and the prosecutors' office about the direction of the inquiry, the first option is highly unlikely. Portuguese newspapers reported yesterday that the police report will state that detectives have not been able to ascertain whether Madeleine was abducted or murdered on the night she disappeared, or her body concealed after an accidental death.

One paper declared that the PJ has concluded it does not have enough evidence to charge the McCanns and will thus clear them. The couple's spokesman said yesterday that he expected their "arguido" status to be officially lifted if the case was shelved, but it is not unusual in Portugal for people to remain official suspects for years on the basis that new evidence could still emerge.

What evidence has been gathered?

Portugal's strict judicial secrecy laws mean that almost nothing is known officially about the lines of inquiry pursued by the investigation team. Yet a culture of successive leaks from within the PJ to the Portuguese media means that vast amounts have been written about the twists and turns of the investigation.

Despite an admission from the PJ's national director, Alipio Ribeiro, that his force had been "hasty" in declaring the McCanns "arguidos", much effort has gone into analysing alleged discrepancies in the accounts of the night of the feared abduction from the McCanns and the so-called "Tapas Seven" – the friends of the McCanns who were eating with the couple at an on-site restaurant.

During interviews last August, it became clear that police were exploring whether Madeleine was given an accidental overdose of a sedative. There has been extensive forensic analysis of Apartment 5A, where the family were staying, and of a Renault Scenic car hired by the McCanns. Reports suggested that DNA found in the car came from Madeleine's body but subsequent leaks said the forensic proof was too badly degraded to support any such conclusion. The McCanns have always denied any involvement in their daughter's disappearance.

Were the McCanns victims of a smear campaign?

The McCanns have privately expressed concern that they are being framed for their daughter's disappearance. Last year Chief Inspector Olegario Sousa, who acted as the public face of the Portuguese investigation for its first four months, made it known through friends that the leaks from within the inquiry were part of a strategy to exert pressure on the British couple to reveal any involvement in Madeleine's disappearance. The result has been a concerted fightback by the couple to clear their names as well as maintain interest in finding their daughter. The Portuguese police have been heavily criticised for some aspects of the conduct of their investigation, which included leaving the crime scene unsecured and leaving the border with Spain open for 12 hours after the feared abduction.

Is anyone else still under suspicion?

Robert Murat, an Anglo-Portuguese property consultant with a house just 100 yards from Apartment 5A, was questioned and made an "arguido" 11 days after the disappearance, apparently after a British newspaper reporter alerted police to his "suspicious behaviour".

The 34-year-old acted as unofficial translator in the early days of the police hunt. An extensive search was carried out of his home, which he shares with his mother. After 10 months of investigation, the PJ returned to Mr Murat possessions seized in May 2007 including clothing and a computer amid speculation that he was no longer a suspect. His lawyer said yesterday that he would only be satisfied when he was formally declared to have no involvement in the case.

What role has the media played in the investigation?

Within a few hours of Madeleine's disappearance, a relative of the McCanns appeared on BBC Radio 4's Today programme to appeal for help in finding the toddler. The subsequent tidal wave of sympathetic coverage took on a more disturbing tone as public appetite for news on the story was sated by leaks suggesting the involvement of the McCanns to the Portuguese media, many of which were subsequently reported again by their British counterparts.

In March this year, the Daily Express and Daily Star published unprecedented front-page apologies to the couple and paid out £500,000 after they started legal proceedings stating they had been "grievously wronged" by the papers' coverage. Mr Murat has also instructed solicitors to examine libel proceedings against 11 publications.

Are we any closer to finding Madeleine?

Prosecutors are not expected to make a formal decision on whether or not to shelve the case until August. Coincidentally, this is when the ban on revealing any details of the PJ investigation also expires. Clarence Mitchell, the McCanns' spokesman, said yesterday that he hoped that any decision to "archive" the inquiry would also entail all police evidence being made public to allow the family and their Spanish-based private detective agency, Metodo 3, to re-examine every line of inquiry. The couple have said they still believe their daughter is alive and will never abandon their hunt to find her.

Has the investigation into Madeleine's disappearance achieved anything at all?

Yes...

* Though progress has been slow, Portuguese authorities deny the investigation has been closed

* If the case is allowed to lie on file, that does not mean it is closed. Information could come to light in the future

* The case has been given a huge amount of resources in Portugal and the UK. The lack of a charge does not mean a lack of effort

No...

* After 14 months, hundreds of interviews and dozens of volumes of evidence, no one has been charged over Madeleine's disappearance

* Despite early optimism, efforts by a private investigation firm to find Madeleine have also foundered

* Not only does the case remain unsolved, but crucial mistakes early on by police may have made their job far harder

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