Detectives from the Metropolitan Police Service conducting the investigative review into the disappearance of Madeleine McCann have now moved to an investigative stage of the inquiry.

Over the past two years the review, whilst not complete, has been in a unique position having drawn together material from the UK, Portugal and Private Investigators from seven different companies. This process has been complex and issues such as translation of material have presented particular challenges. To date some 30,500 documents have entered into the process which has generated in excess of 3,800 actions. The actions that we have completed have generated new findings and new witness evidence.

Our review has sought to prioritise the material, ensuring we are doing everything possible to understand what happened to Madeleine. In the absence of any clear evidence to the contrary we maintain our belief that Madeleine may still be alive.

The MPS has conducted 16 visits to Portugal and we have met and shared our findings with key members of both the Policia Judiciaria and Judicial Authorities. Our relationship is positive and we are grateful for the co-operation we have received thus far.

We are satisfied that our review has now progressed to a position where we have identified 38 persons of interest. These individuals are from a number of European countries and we are now at an advanced stage of dialogue with each country. Over the coming months we will be conducting assertive enquiries, with the assistance of host countries to establish more information about the individuals concerned and any potential involvement.

Twelve of the persons of interest are UK Nationals who we believe were in Portugal at the time Madeleine went missing.

Officers, under Operation Grange, have formally requested the Crown Prosecution Service submit an International Letter of Request to the Portuguese Authorities seeking assistance in obtaining evidence relating to lines of enquiry they wish to pursue. This has been done with the full support of the UK Government.

The MPS has requested, in accordance with accepted Mutual Assistance practice, that a small number of UK officers are present in Portugal whilst the enquiries are undertaken.

The MPS will be as open as our operational priorities allow but in the context of this complex operating environment we appeal for media restraint. There is a real risk that a lack of restraint could serve to seriously undermine our ability to progress.

 Detective Chief Inspector Andy Redwood, heading Operation Grange, said today: "We, and the Portuguese authorities, remain completely committed to finding out what happened to Madeleine, and everything we do is utterly focused on her best interests.

"We continue to believe that there is a possibility that Madeleine is alive.

"It is a positive step in our hunt for Madeleine that our understanding of the evidence has enabled us to shift from review to investigation.

"We have identified 38 persons of interest from a number of European countries. 12 of those people are UK Nationals who we believe were in Portugal at the time Madeleine disappeared.

"Our working relationship with the Portuguese Police is positive and now that we have moved to investigation we are requesting further specific assistance through normal judicial routes.

"We remain in close contact with Kate and Gerry McCann and they are updated on our current position.

"We continue to appeal for information. If you were at the resort of Praia da Luz between 28 April and 3 May 2007, either on holiday or in residence in the resort during this period, particularly in the vicinity of the Ocean Club, and you have not been spoken to by police either here or in Portugal then please call us on 0800 096 1011 if you are within the UK. The number for non-UK residents is +44 20 7158 0126. Alternatively if you do not want to speak to us directly you can contact Crimestoppers on 0800 555 111.”