Police investigating the disappearance of St Andrews student Duncan Sim say there is no suggestion a criminal act has been involved.
However, Chief Inspector Steven Hamilton told a press conference on Tuesday that he was not ruling anything out.
“At this stage nothing in my investigation suggests any criminality whatsoever,” he said.
“That doesn’t mean that at any stage I am ruling that out. I remain completely open minded in relation to this investigation.
“At the moment it is a missing person inquiry and absolutely nothing in the inquiry has suggested that there has been any criminality.”
Chief Inspector Hamilton spoke to reporters just yards from the Madras Rugby Club pavilion, which has been used as a base for volunteers helping the search effort and is where Duncan was last seen nearly a week ago.
The British Army have been assisting police and the coastguard in the search for Duncan.
The 19-year-old had attended at a social event at the pavilion last Wednesday and has not been seen since he left the venue at around 11pm that night .
The alarm was raised after he failed to arrive back at his accommodation at Agnes Blackadder Hall.
An image captured on CCTV of Duncan leaving the halls on the night he went missing has been released by police.
Duncan is described as being 6ft tall and of medium build.
He has brown hair and green eyes, and when he was last seen he was wearing a grey suit jacket, a white shirt and a blue and white tie.
Chief Inspector Hamilton made a renewed appeal for the public’s asistance in helping officers trace Duncan, who is a first year Chemistry undergraduate at the university.
He said: “Both the family and obviously ourselves the police are very concerned for Duncan’s safety.
“We have a substantial team of officers involved in trying to find Duncan. More than 100 officers are involved, in the investigation and the search, with numerous specialists resources from across Scotland assisting.
“Our concerns, now that’s it’s nearly a week since he went missing, are growing significantly.
“I would appeal to any members of the public who were in the area of Madras Rugby Club or further afield within the St Andrews area who may have seen anybody fitting Duncan’s description that they contact us on 101.”