POLICE probing the disappearance of Margaret Fleming have followed leads all the way to America — as the detective heading the search today acknowledged that 'something sinister' may have happened to her.
In an exclusive interview, Detective Chief Inspector Paul Livingstone told the Telegraph how his team of dedicated officers are also endeavouring to trace every Margaret Fleming in the UK and Channel Islands as the intensive inquiry reaches its six-month mark tomorrow.
More than 1,700 people and agencies have been contacted as part of the exhaustive effort to trace Margaret, 37 — who was reported missing by her carers, Edward Cairney and Avril Jones, on October 28 last year.
However, the last independent sighting of the missing woman — who hails from Port Glasgow — was nearly 18 years ago, at a family gathering in December 1999.
With no trace whatsoever of Margaret over that time, and no new leads, when asked by the Tele about the possibility of foul play DCI Livingstone declared: "It would be foolish not to consider that something sinister has happened."
A fingertip search of Seacroft — the isolated river-edge house Margaret shared with Mr Cairney, 75, and Ms Jones, 56, in Inverkip — and its grounds has now been completed and the police unit based there for months has now packed up.
But officers still have no clue as to where Margaret may be, or what might have happened to her, ahead of a planned briefing with the Crown Office to discuss the state of the inquiry.
DCI Livingstone said: "We have finished our examination of the house and grounds and we are now poring over a number of documents to establish anything that can point us in the right direction.
"We've been in touch with over 1,200 different persons and agencies to ascertain information and, frankly, verify if Margaret is still alive.
"We await some 200 outstanding responses in this regard.
"Over and above that we have taken statements from 500 people, including Margaret's extended family and the family members of her carers.
"She has extended family in the United States and we have three more people to speak to there.
"Once we have everything we will review the situation and then have a discussion with the procurators fiscal office to see if they consider that there is anything further that we should do.
"If there are no further avenues we work on the premise that Margaret is still alive and this remains a missing person inquiry.
"We can all have our thoughts about this case but if you go down that track then focus could be lost and something missed."
It has also emerged that a death notice pertaining to a relative of Margaret that was published in the Telegraph in 2001, which was initially submitted without her name on it before being amended, has also been examined by the investigation team.
DCI Livingstone said of that development: "It is something that we've looked at, but it could have been a typing omission at the time and wouldn't read too much into that at the moment." 
He added: "Margaret could have wandered off and come to harm; she may have been of low mood and come to harm; there may have been an accident.
"It would be foolish not to consider that something sinister has happened.
"That is still a consideration and has been a consideration from day one, but there is no evidence to suggest anything other than this is a missing person situation."
DCI Livingstone has also issued a fresh appeal for information from anyone who has had cause to visit the home Margaret shared with Mr Cairney and Ms Jones since 1999.
He said: "There is still a vast amount of work to do and we are keen to trace anyone — be it a delivery driver, a cold caller or a regular visitor — to Seacroft between December 1999 and October last year to contact us."
Mr Cairney and Ms Jones — who have told police that they last saw Margaret at 5.40pm on October 28 last year — have previously declined to issue a public appeal to help find her and DCI Livingstone confirmed that this remains their position.
Before Margaret started living with the couple, she’d stayed with her father Frederick in Port Glasgow until his death in 1995.
She then lived with her grandparents and mother, also Margaret, until moving in with Mr Cairney and Ms Jones in 1997.
DCI Livingstone said: "It is a possibility that Margaret will be declared dead by the procurator fiscal, but it is then a question of how did she meet her death."
If you can help with the inquiry contact police on 101.