A detective searching for missing chef Claudia Lawrence has said he is "actively pursuing new leads" on the sixth anniversary of her disappearance.
Detective Superintendent Dai Malyn of North Yorkshire Police said his team had moved forward since reviewing the case in 2013 and may make more arrests. Mr Malyn said: "In the months since we started our review, we have made very significant progress."
The detective warned anyone who had not yet revealed information about their relationship with Ms Lawrence or the events in the days leading up to her disappearance to come forward or risk being arrested.
Ms Lawrence was last seen on Wednesday, March 18, 2009 and was reported missing by her father on Friday, March 20 after concerns were raised when she failed to turn up for her 6am shift at York University.
Police believe Ms Lawrence has been murdered.
A 60-year-old man was arrested last year in connection with her disappearance and suspected murder but was later released without charge. A 47-year-old man is on bail on suspicion of perverting the course of justice.