Kate McCann wrote a heart-rending letter to the head of the Portuguese police investigation begging for information about the search for her daughter.

She wrote to Paulo Rebelo after he replaced disgraced Goncalo Amaral as chief investigator of her daughter's disappearance and pleaded to be kept informed about the hunt for Madeleine.

The letter, dated 4 December last year, is included in the huge dossier of evidence assembled about the case which was made public this week.

In it, Mrs McCann, 40, from Rothley, Leicestershire, said Madeleine was "the most precious thing in our life". She said that the period since her daughter went missing had been "the most difficult, sad and unbearable time that any parent could possibly imagine".

She called for an end to " fingerpointing blame" and said her pain and anxiety were "indescribable".

But Mr Rebelo never replied. Mrs McCann received only a formal notification that her letter would be placed in the police file.

Mrs McCann said she and her husband Gerry, also 40, felt helpless in the face of the accusations against them, published after they were named "arguidos", or formal suspects, last September.

She said the lack of communication between the police and the family was "torture". She wrote: "I am appealing to you as a fellow human being to work with us (if possible include us) and to remember that we are Madeleine's parents and have needs... Lack of communication and a void of information, particularly as the parent of a missing child, is torture."

Mr Rebelo was appointed head of the investigation on 9 October following the removal of detective Goncalo Amaral after he criticised the British police in a Portuguese newspaper interview.

The couple's official spokesman Clarence Mitchell said today: "Kate certainly didn't get a personal response from Paulo Rebelo."

Files from the Madeleine dossier also show that Portuguese police withheld potentially crucial information after the three-year-old's disappearance in May last year. This included sightings and e-fits of possible suspects.

Private detectives for the McCanns are pursuing a report today that a girl calling herself "Maddy" was seen in Amsterdam days after Madeleine vanished from her family's holiday apartment in the Algarve resort of Praia da Luz.

Party shop assistant Anna Stam, 41, said she spoke to a girl aged three or four who said her name was "Maddy".

The girl had been with a man, a woman and two other children, accordingto Ms Stam. She approached the assistant and asked in English without an accent: "Do you know where my mummy is?" Told that her mother was at the back of the store, the child replied: "She is not my mummy ... She is a stranger, she took me from my mummy."

The Dutchwoman said the girl looked "very much like" Madeleine.

The report was sent to the Portuguese authorities on 18 June last year but it is not clear what action was taken.

Lawyers for the McCanns are studying the police files for fresh leads that their private detectives can follow up in their own search. Other revelations from the police files include a map sketched by Jane Tanner, one of the friends on holiday with the McCanns, showing the route taken by a man she believes was abducting Madeleine.

Representatives of the McCanns are said to be in talks with the BBC's Crimewatch programme in a bid to reinvigorate the search by filming a definitive reconstruction of events.

The proposal would see BBC film crews travel to the Algarve to put together an international appeal drawing upon all the new details.

A family friend said: "The call will be made today to see if we can make it happen."

• 

  Picasso & Modern British Art - review

  Tate Britain's exhibition is an exploration of Picasso's influence on seven English contemporaries

  ---

• 

  Ken Livingstone's friends in the East

  The Mayor of Tower Hamlets defeated Labour to be elected. Livingstone not only backed him but some of Ken's key players are now at the heart of running the council. Stephen Robinson reports

  ---