A man missing for more than a month might have been “out of his depth in some kind of criminal activity”, police have said.
Mohammed Shar Subhani, 27, also known as Shah Khan, was reported missing on 7 May after he failed to return to his home in Hounslow, west London.
The Met believe he may have dealt cannabis after he lost a courier job.
Two men have previously been arrested on suspicion of murder and police have offered a £20,000 reward.
It is being offered for both information leading to his whereabouts, and also for information leading to the identification, arrest and prosecution of anyone connected with his disappearance.
‘Wall of silence’
Mr Subhani was reported missing shortly before midnight by his family, who saw him last at 12:30 BST on 7 May.
Police said information “suggests [he] was in debt” and he attended Acton Police Station between 13:47 and 14:31 in the hope of collecting £4,800 from “a matter that was not proceeded with”.
Detectives believe he then had a meeting at a business on an industrial site in Derby Road, Hounslow, where he met an associate who owed him £5,000, which is thought to have been paid.
He had two phones which connected to the network at 15:55 and 21:04 and the later call was still within the Hounslow area
Police have also appealed to find Mr Subhani’s white Audi Q3, registration LC67 CXS, which has still not been found.
Det Ch Insp Noel McHugh said: “When you remove the possibility that he’s taken his own life, left the area voluntarily, or had an accident, there is a strong suggestion that there has been third-party involvement in him going missing.
“I believe that Mohammed has got out of his depth in some kind of criminal activity.
“At this time there is a wall of silence and people are in the know, we need those people to come forward and tell us what they know.”
The arrested men have been bailed until mid-June, the Met said.