Amsterdam police have issued a missing person’s notice for a 24-year-old Scottish tourist who was last seen early on Sunday morning.

Chris Nelson, who lives in Dusseldorf, went out for a walk around 06.00 hours, saying he could not sleep, and has not been seen since.

‘This is something he often does,’ fiancée Stefanie told local broadcaster AT5. ‘He went out without jacket, keys and passport but did not come back. We’ve all tried to phone him but his phone is off and he’s vanished.’

Police say they have no idea what has happened to Nelson. His family have ruled out any involvement with drink or drugs at the moment of his disappearance. He was due to drive back to Germany on Sunday morning and was ‘very responsible’ about this sort of thing, his mother is quoted as saying.

Nelson’s walk began on the Recht Boomsloot in the heart of the city centre where the couple were staying with a friend. He was wearing grey jeans and a black hooded sweatshirt, black Nike sneakers and glasses.

People who may have seen him are being urged to contact the police on 0800-6070.