Met homicide unit searching for missing PC Gordon Semple
The Met Police homicide unit is investigating the case of a serving police officer missing for five days.
PC Gordon Semple, from Greenhithe, Kent, was last seen on 1 April in the London Bridge area of London.
He had a work meeting at the Shard's Shangri-La hotel and left at about 12:30 BST. He was seen on CCTV in Great Guilford Street at 15:00 BST.
His partner reported him missing later that night. His niece Kerry Nicholas said the family was "very worried".
She told BBC News: "This is completely out of character for him.
"He is just a very outgoing, sociable guy. Very happy-go-lucky.
"He wasn't on any medication or anything and we have no reason to suspect he would just disappear without telling anyone.
"Nothing like this has ever happened to him before."
The family said he enjoyed travelling to Thailand, but was not aware he had been planning any trips abroad.
PC Semple is described as white, 5ft 10ins (1.7m) tall, of a large build with a shaved head. He was last seen wearing brown shoes, dark trousers and a lilac shirt.
The 59-year-old is originally from Inverness and works with the Met Police anti-social behaviour unit in Westminster.
He has no children but still has family in Scotland.
Det Ch Insp Cliff Lyons said the force was keeping an open mind as to the circumstances of PC Semple's disappearance.
The case was being treated as a high-risk missing person's inquiry, but because of concerns for his welfare the homicide unit was taking the lead, the Met said.
Anyone with information can call the Met anonymously or contact Crimestoppers.