A man in his 50s has been arrested on suspicion of murdering missing University of York chef Claudia Lawrence.
Miss Lawrence was 35 when she disappeared from her home on Heworth Road in 2009.
Her body has not been found.
Last month detectives investigating Miss Lawrence’s disappearance re-examined an alleyway behind her home for fresh clues.
A police spokesman said searches were being carried out in relation to the disappearance and were expected to continue for a number of days.
Speaking to the Guardian, DS Dai Malyn, of North Yorkshire police, has urged not to identify the arrested man.
He said: “To ensure the investigation and legal process are not compromised or potentially damaged in any way during this critical phase in seeking the truth about Claudia’s disappearance, North Yorkshire police strongly advises the media and members of the public against identifying the man who has been arrested.
“This includes naming or publishing images of the man on traditional media platforms or social networking sites.
“I urge everyone to show restraint and patience while we carry out these very important inquiries.”
Claudia’s family has been notified about the arrest and is being supported by trained officers, North Yorkshire Police said.
Miss Lawrence, who lived in Heworth, worked at the University of York as a chef.
North Yorkshire police launched a review of the investigation last year after a new major crime unit was established by the force.
Anyone with information is urged to contact North Yorkshire Police on 101, selecting Option 1, and passing on the details to the Force Control Room by quoting “Claudia Lawrence” before doing so.