The search for Claudia Lawrence is being hampered by the withholding of vital information, police have said 10 years after she was last seen.

Monday marks a decade since Lawrence, who was a chef at the University of York, disappeared at the age of 35.

North Yorkshire police have been treating the case as a suspected murder investigation. Nine people have been arrested or interviewed under caution, and police submitted files to the Crown Prosecution Service (CPS) in relation to a number of individuals. There was insufficient evidence to bring charges.

On the tenth anniversary of when she was last seen, police said they were still waiting for information from the public to help them make significant progress.

Monday marks the tenth anniversary of the disappearance of Claudia Lawrence. Photograph: North Yorkshire Police/PA

Det Supt Dai Malyn said: “It remains the case that we strongly suspect key and vital information is being withheld that could provide the breakthrough that we all want to see, not least Claudia‘s heartbroken family.

“Unless we get information or intelligence to suggest that Claudia came to harm as a result of an opportunity taken by someone unconnected to her, me and the team still strongly believe the answer lies locally.

“As with some recent cold case successes, the breakthrough has come from the public and we still have confidence that this will be the case.”

Immediately after Lawrence’s disappearance on 18 March 2009, searches were focused on the route between her home on Heworth Road and the University of York. Hundreds of officers across various forces were initially involved but the investigation has been scaled back over the years.

Malyn said the investigation had so far been hindered by a lack of CCTV around Lawrence’s home, as well as the fact that she had neither a smartphone nor a social media profile when she vanished.

“We know also that her mobile phone didn’t leave the area before it left the phone network,” he added “This again is a reason I don’t believe she fell victim to an attack by a stranger.

“Also, we have no actual scene where something untoward may have happened to her despite fresh forensic assessments of her house, car and other locations.”

The force said members of the public were still coming forward with information. Malyn said that despite being well-intentioned, much of this was speculation or theory.

“The call we really want is the one that helps piece together the parts of the jigsaw we already know regarding her last movements and people she associated with and places frequented,” he added.