Detectives are making a fresh appeal for information about a Polish man who went missing "without a trace" in Leicester four years ago.
Grzegorz Witkowski, 48, of Highfields was last seen by a friend on 12 December in 2009 as he left a party.
He was due to have a doctors' appointment the next morning but never arrived.
Leicestershire Police said his death has been treated as a "no body murder" case since a review in 2012.
Mr Witkowski, who was a mechanic and also worked in the recycling industry, was originally from Poland but had spent much of his time living and working in England.
In September 2012 two men were arrested in connection with the incident, but both were released with no further action.
He is described as white, 5'5" tall, of slim build, with short brown hair and brown eyes.
Det Supt Neil Castle, who is leading the investigation, said: "Since a full review of the case was carried out in 2012 we have been conducting this enquiry as a 'no body murder' investigation.
"This means we have put in the same resources and carried out enquiries as we would in any other murder investigation.
"We believe the answer to what happened lies in the Polish community.
"We are appealing now to anyone who has heard about what has happened to Grzegorz or believes they could have a small piece of information which could help.
"As a result of Grzegorz's disappearance his wife over in Poland is struggling financially.
"Christmas is a time for families and this will be the fourth year Grzegorz's will have been without him."