UK police have told the parents of Amanda Dowler the missing schoolgirl is probably dead.
Hampshire detectives say they are unlikely to see Amanda - also known as Milly - alive following her disappearance on March 21.
The officers have been in discussions with colleagues from the Metropolitan Police who are investigating two other cases of missing women.
They have swapped notes on Elizabeth Chau, 19, and Lola Shenkoya, 27, both of whom disappeared in the Ealing area of London in 1999 and 2000.
The spokeswoman said: "It's very common in cases like this to do that. But at this stage, there is no evidence to link this case with any other crime, including these two crimes in Ealing, but as you would expect we are looking at all possible scenarios."
She added that dozens of detectives had met this week at the National Crime and Operations Faculty at Hampshire Police headquarters to discuss the case of Amanda Dowler.
The search for the Surrey teenager - whose 14th birthday is on Tuesday - has thrown up little clues since she vanished while walking home in Walton-on-Thames.
A Thames Valley Police spokeswoman says parents Bob Dowler, a 50-year-old IT consultant and mother Sally, 42, a teacher, had been told by senior officers to accept the fact she may have been killed.
She said: "There has been no actual evidence to suggest that Amanda is either dead or alive, but as time has gone on the less likely it has become that she is alive and we have become more concerned.
"We are still officially treating this as a missing person inquiry as there has been no evidence, and no body found. But we are taking it as a serious incident and resourcing it fully - as much as we would a critical situation/murder inquiry ... We have not ruled anything out."