The body of 17-year-old Georgia Williams - who has been missing since Sunday - has still not been found, despite the arrest of a 22-year-old man over her murder, police said.
The man, from Wellington, Shropshire, had originally been arrested in Glasgow for the alleged kidnap of the teenager and has since been returned to Telford.
Superintendent Nav Malik, Telford and Wrekin police commander, said: "I make it very clear, folks, that we have not found Georgia Williams at this moment in time.
"She remains elsewhere - we are not quite sure where. We are really, really keen to identify where she may be, her whereabouts and I urge the public to support us in trying to find out where she may be." He added there were more than 50 detectives are working on the investigation.
Georgia has not been seen since telling her parents she was going to see friends at 7.30pm on Sunday. Police said she had her mobile phone with her when she left, but the last calls and text messages were received from the device at about 8pm that night.
On Wednesday, police forensics teams were searching a semi-detached house in Wellington where neighbours said a Jamie Reynolds lived with his parents.
Mr Malik said police were still keen to trace the movements of a silver Toyota Hiace 300 GS van which the man in custody had access to, which was seized in Glasgow on Wednesday. The van, which has the number plate CV06 ASV, is believed to have left Wellington at about noon on Monday, travelling to Oswestry, Rhyl, Chester and Kendal before reaching Glasgow at about midday on Tuesday.
Mr Malik has previously said that Georgia's disappearance was "completely out of character". He described the man in custody as a "friend" of the missing girl, but not her boyfriend.
Georgia, who is white, is described as 5ft 3in, slim with long dyed red hair, and was last seen wearing a waist-length black leather jacket over a white T-shirt which has a London bus motif on it. She was also wearing black skinny jeans and flat, black suede slip-on shoes.
Police have been searching woodland and have taped off an area in a nature reserve about 17 miles from Wellington. Uniformed officers and a police tent are currently at Brown Moss Nature Reserve, Shropshire.