A man who was last seen being bundled into the back of a car is feared dead by police.
The last known sighting of Aron Kato, 28, was on CCTV footage which showed him being chased and pushed to the ground by a man in Ilford, east London.
He has not made any contact with his friends or family since then.
Det Ch Insp Mick Norman said: “I am deeply saddened that we have had to accept that this is now a murder investigation.”
The CCTV was recorded in Ley Street at about 04:30 BST on 18 April.
‘Genuine family man’
He was then bundled into a dark-coloured BMW with the registration number RF12 0ZA, police said.
Seven people, aged between 25 and 39, have been arrested on suspicion of kidnap and bailed or released under investigation.
Mr Kato, who became a father shortly before his disappearance, has not been found despite several appeals for information.
His partner, Chanel Naidoo, and mother to his six-month-old son described him as “a genuine family man”.
“Aron is the kindest and most caring person and he is the best partner, father, son, brother and uncle and we need him home back with us where he should be,” she added.
A £10,000 reward has been put up by Crimestoppers for information leading to the arrest and conviction of the people responsible for Mr Kato’s abduction and murder.