The Crown Prosecution Service will consider bringing charges against four men arrested on suspicion of murdering missing Claudia Lawrence, police have said.
The university chef disappeared on her way to work in York in March 2009 and no sign of her has been found since.
The four men, in their 50s and from the York area, were arrested earlier this year and were currently on bail, North Yorkshire Police said.
A file of evidence will be handed to the CPS once it is prepared, and assessment by lawyers of the case will take some time, the force said.
The officer in charge of the inquiry stressed it remained active and urged people not to identify the men in question.
Detective Superintendent Dai Malyn said: "This is to ensure the investigation and legal process are not compromised or potentially damaged in any way.
"This includes naming or publishing images of the men, their home addresses, places of work, their vehicles and properties on traditional media platforms or social networking sites.
"Your co-operation and support is greatly appreciated by the investigation team."
Anyone with information that could assist the investigation should contact North Yorkshire Police on 101.