NEW forensic methods not available at the time of Claudia Lawrence's disappearance provided many of the case review's key new leads.
A large element of the Major Crime Unit's work on the review involved crime scene investigators revisiting the York chef's terraced home in Heworth, York.
Crime Scene Investigators (CSI) initially expected to remain at her home for two weeks, but the detailed examination at the scene lasted nearly two months.
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The investigating team called on the latest expertise from the National Crime Agency, along with forensic specialists and advisers to work with CSI units from the region.
As a result, fingerprints and DNA from individuals not yet identified were found in her home. The property has now been handed back into the care of Miss Lawrence's father, Peter.
DNA was also found belonging to an unknown man on a cigarette butt in Miss Lawrence's Vauxhall Corsa.
Miss Lawrence's Vauxhall Corsa
The car was in a local garage at the time of the disappearance, but head of the Major Crime Unit, Detective Superintendent Dai Malyn, said the profile did not relate to any man who had yet come forward.
He said: "We are keen to eliminate people who have been inside Claudia's home before and after her disappearance.
"The elimination process is simple, we just encourage people to come forward. Not doing so only raises questions as to why you wouldn't.
"There is also other DNA material from items examined in the house that have been recovered. Forensic work is ongoing in respect of these items."
Det Supt Malyn said the examination of Miss Lawrence's home pointed to the fact she had left for work on the morning of Thursday, March 19, 2009.
He said: "From the review of all the evidence available, including the fact that Claudia's bed was made and it appears that she had eaten breakfast and brushed her teeth, it is our belief that she had left for work on the morning of Thursday, March 19, 2009.
"What is unusual is that Claudia's GHD hair straighteners - model number 14.4.1B and purchased in May 2007 - were missing from her home.
"From our inquiries, it is doubtful that she would take them to work in her blue and grey Karrimor bag which has also never been found."
Police also revealed that a quantity of blonde hair dye was found in her house.
Det Supt Malyn said: "We know prior to her disappearance she was a brown colour but she did lighten her hair.
“Was she planning to go more blonde or colouring anybody else's hair?"
DETAILS of North Yorkshire Police's new leads will be broadcast on BBC1's Crimewatch at 9pm tonight , when officers are set to release further information.
*Anybody with information that could assist the investigation is asked to contact North Yorkshire Police on 101, select option one, and pass details to the Force Control Room, quoting "Claudia Lawrence".
*Information can also be passed anonymously to the independent charity Crimestoppers on 0800-555111, quoting "Claudia Lawrence, North Yorkshire Police".
*Peter Lawrence, Miss Lawrence's father, has a dedicated website, Find Claudia
*The Claudia Lawrence appeal is also supported by the Missing People charity