Paige left the family home following a row
An anonymous note has been sent to police investigating the disappearance of Lancashire teenager Paige Chivers.
The 16-year-old walked out of her family home in Bispham in August 2007 following an argument.
Officers said a anonymous note sent to Bispham police station suggested someone knew what happened to Paige. They want the sender to contact them.
Earlier this week, police searched a garage in Cranbrook Avenue, Bispham, and carried out forensic tests.
Leaflets with details of her disappearance have also been handed out to people living in the area.
Detectives said they were not prepared to go into more detail about what the note said.
Det Supt Kevin Toole, of Lancashire Police, said: "This is the most heavily-resourced major investigation that has been going on in the force over the last 12 months.
"Detectives have been drafted in from across the force and our commitment to finding Paige has not changed since the day she was reported missing.
"Ultimately, we want the same as Paige's family, which is for Paige to return home safety, but sadly as the months and years pass, this is a likelihood that decreases each day.
"We have received an anonymous note of interest which suggests someone knows what has happened to Paige. I am not prepared to disclose the content of this note but it was sent to Bispham police last month and I would urge the person that sent it to get back in touch."
Paige had been known to visit the Station Hotel pub, in Dickson Road, opposite Blackpool's bus station, between summer 2006 and Christmas 2006 and also in April and June 2007.
Police said they believed the pub was a focal point for Paige but needed the people that knew the teenager to contact officers and explain why.
Paige was last seen carrying a blue or purple suitcase and boarding the number 11 bus at Ashfield Road, Bispham.
She is described as white, 5ft 5in tall, with brown hair and a Playgirl tattoo on the back of her neck.