Police leading the hunt for missing Leah Croucher have released what they believe is a new image of her captured on the day she went missing.
Tuesday marks the third anniversary of then 19-year-old Leah's disappearance in Milton Keynes.
The blurry image taken at Furzton Lake shows a person dressed in black, who may or may not have been Leah, on the day she disappeared.
The last confirmed sighting of Leah was at 8.16am on CCTV in Buzzacott Lane, Furzton, on the morning of 15 February, and the last activity on her phone was just after 8.30am that day.
Thames Valley Police hope the image will be widely shared and said it showed several other people who they hope might have information.
Det Ch Insp Andy Howard said: “The image we are releasing today is not of a high quality, but I am hoping that somebody will recognise themselves as being in this picture.
“I am keen to hear from the group of people in this image; it may be that you regularly walk in this area and will recognise yourselves.
"I would also like to hear from the person in the image walking her dog."
Police said it was not possible to be certain the black-clad person in the picture was Leah, but that witnesses in the area of the lake had described seeing a young woman in black clothing who was described as distracted or upset, and possibly using her phone.
DCI Howard said previous appeals had failed to establish the identity of the woman.
Leah's family said it was "soul-destroying" not knowing what has happened to her and they were desperate for anyone with information to come forward.
The police appeal came as her family released an emotional statement to mark the three-year anniversary of her disappearance.
In it, they said they were determined to keep looking and urged the public to keep helping them. A year ago they said they still dreamed of Leah as they issued an appeal for her to come home.
In the statement released today, they said: "It has been three long, desolate years since our beautiful and wonderful daughter Leah, vanished without a trace on her way to work.
"We still have no answers as to why. No clues as to what happened. No idea as to where or how she is.
"It is impossible to stay positive after all this time, it was difficult at the start of this, but now, the task is so futile, our lives are so bleak.
"It is harder each day to tell ourselves that today will be the day that we get answers... today we find out what happened three years ago.... today we get our treasured daughter back.
"Each day is torture. Each day feels like an eternity of pain and despair."
There is currently a £20,000 reward for help to find Leah.
DCI Howard said he was appealing who people who live, work or commute in the areas Leah used regularly.
She walked to work in Knowlhill most mornings, he said, and on 15 February she was seen on CCTV in Buzzacott Lane, Furzton at 8.16am. From there, police believe she walked past Tellytubby Hill on Dulverton Drive.
"From that point we believe that Leah would have either taken a route north around Furzton Lake or along Loxbeare Drive into Shenley Lodge and north along Faraday Drive," said DCI Howard.
“This area is a well populated residential area with people commuting, doing the school run or exercising. Given how busy the area is I find it hard to believe that this CCTV clip of Leah at 8.16am is the last time that we know she was seen."
“At around this time a witness saw a female matching Leah’s description walking past Tellytubby Hill, approximately 150 yards after the sighting in Buzzacott Lane.
From the information the witness provided we believe it is likely that it is Leah, however as Leah is not known to the witness it is not possible to say with certainty."
He urged other witnesses who may have seen the woman to come forward.