The detective leading the investigation into the disappearance of university chef Claudia Lawrence has thanked the public for “new information” as a search operation continues.
Officers are conducting detailed searches of an area around a popular fishing spot a few miles from the centre of York.
The operation in and around the gravel pits near the village of Sand Hutton began on Tuesday.
On Thursday, Detective Superintendent Wayne Fox said: “I thank the public for the positive responses and new information received in support of the current phase of the investigation.
“Our focus is on finding Claudia and bringing those responsible for her disappearance and suspected murder to justice.”
Mr Fox has not disclosed what information has prompted the search activity 12 years after Ms Lawrence went missing.
Earlier this week, Ms Lawrence’s mother, Joan, said the new searches have left her in “utter shock”.
Mrs Lawrence told reporters she was “very, very churned up” about the latest developments in the investigation.
Police believe Ms Lawrence – who lived in the Heworth area of York and worked at York University – was murdered, although no body has ever been found.
She was last seen on March 18 2009. North Yorkshire Police has conducted two investigations and questioned nine people in relation to her disappearance and suspected murder, but no charges have ever been brought.
Speaking after he took over as senior investigating officer in the case earlier this year, Mr Fox repeated the belief that several people know, or have suspicions about, what happened to the 35-year-old.
At the scene on Tuesday, where a road and a large area of woodland had been cordoned off and police could be seen searching the undergrowth with sticks, the detective said a number of specialist officers and staff, including underwater search teams and forensic experts, were likely to be at this location for a number of days.
Ms Lawrence’s father, Peter, died earlier this year without knowing what happened to his daughter.
He had campaigned tirelessly to get answers to the puzzle of her disappearance and spent years arguing for what became the Guardianship (Missing Persons) Bill – also known as Claudia’s Law – which allows relatives to take control of their missing loved ones’ financial matters.
Martin Dales, a friend of Mr Lawrence, said this was the first development in the case since his death, and described the situation as “bittersweet”.