An extra 10 detectives have been drafted in to help search for the missing Blackpool teenager who vanished more than four months ago.
More than 30 officers are now dedicated to finding the 14-year-old who disappeared without trace on November 1 last year.
Her frantic family, of Buchanan Street, Blackpool, say they have been torn apart by her disappearance. They are also facing the agonising possibility of Charlene's 15th birthday, later this month, without her.
Det Supt Paul Buschini, who is leading the inquiry, said: "Charlene has been missing for some time now and with every day that passes we become more anxious for her safety.
"Sometimes I have bad days when I fear the worst. Then we will get a glimmer of hope in the shape of a possible sighting or a new lead, and things seem much more hopeful.
"While we are constantly looking at new lines of inquiry, we are still searching for a concrete lead to help us locate Charlene.
"We have still not had a confirmed sighting since she disappeared, which is very concerning."
Charlene was last seen in Blackpool town centre on November 1, the evening she disappeared.
Detectives are still searching for two men in connection with their inquiry who they think may be able to help. One of these is a man known as Ronnie who met Charlene on a regular basis and gave her money.
Charlene's mum, Karen, said today: "It is torture for the family, especially with Charlene's birthday approaching. I now wonder if she is in the area at all, or somewhere else."
Charlene is registered with the National Missing Persons Helpline which today reported an unconfirmed sighting in Blackpool of missing Margate girl Melissa Goddard, 15.
n Anyone who has seen Charlene or Melissa should call the confidential NMPH on Freephone 0500 700 700.