Police have drained a lake as part of their investigation into the disappearance of Claudia Lawrence.
The pond at Sand Hutton Gravel Pits was drained and searches at the site could continue for a number of days, North Yorkshire Police said.
Ms Lawrence, a 35-year-old chef, lived in the Heworth area of York and worked at the city’s university.
She was last seen on 18 March 2009 and, although detectives believe she was murdered, her body has never been found.
Nine people have been questioned during two investigations into her disappearance but no charges have been brought.
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.”
Last week Mr Fox thanked the public for the positive responses and information received in support of the current phase of the investigation.
He did not reveal what had prompted the search at the lake.
Ms Lawrence’s mother, Joan, said the new searches had left her in “utter shock”.
She told reporters she was “very, very churned up” about the latest developments in the investigation.
Ms Lawrence’s father, Peter, died earlier this year without knowing what happened to his daughter.
For years he had campaigned to get answers about her disappearance, also 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, describing it as “bittersweet”.