A University of Edinburgh research fellow has gone missing after boarding a flight to Switzerland for a computer science conference.
Fergus McInnes, 51, got on the EasyJet flight from Edinburgh to Geneva at 09:35 on 9 September.
But police said he did not check into his hotel or attend the conference.
Mr McInnes, who lives in St Leonard's Bank in Newington, also failed to board his scheduled return flight, and his whereabouts remains unknown.
He is described as white, 5ft 7ins, slim and with ginger hair.
Mr McInnes works at the University of Edinburgh's School of Informatics.
A university spokesman said: "This is a missing persons investigation and we are assisting Police Scotland with their enquiries."
Police Scotland said they were very keen to hear from Mr McInnes or from anyone who has information regarding his whereabouts.