Police have gathered a full DNA profile of missing schoolgirl Shannon Matthews which will be used to search places she may have been since her disappearance.
Detectives said the profile, along with her fingerprints, had been pieced together from personal items including schoolbooks owned by the nine-year-old.
Det Supt Andy Brennan made a fresh appeal to the community on Tuesday.
Shannon was last seen on 19 February on her way home from Westmoor Junior School in Dewsbury, West Yorkshire.
More than 200 officers and 60 detectives are involved in the investigation which Mr Brennan said amounted to 10% of West Yorkshire Police's operational strength.
Sniffer dogs have been used to search more than 500 homes in Dewsbury and detectives have also questioned known sex offenders in the area.
Mr Brennan said the youngster was carrying a plastic bag which contained a two-piece pink swimming costume with a blue fish design and a blue striped towel.
He said the schoolgirl may have headed in the direction of Heckmondwike Road or along Church Lane and on to Staincliffe Road.
"My appeal is to focus on the people of Dewsbury Moor," he said.
"I would like to thank them for their help and assistance.
"However, I would ask them to think back to two weeks ago and on that Tuesday afternoon. Did they see Shannon or anything unusual?"
Mr Brennan added that police would continue their efforts to find Shannon but that they were prepared for any eventuality.
Shannon's mother Karen Matthews made a plea on Monday for anyone who was holding her daughter to let her go.
She said she accepted police had to carry out criminal checks on members of her family and that her daughter's disappearance had now made her question her trust for friends and wider family.
"The family don't feel safe any more - it has broken the family apart," said Ms Matthews.
"It makes me think I can't trust the people who are really close to me anymore."