A 21-year-old man from Hertfordshire has been arrested on suspicion of murder by police investigating the disappearance of a van driver.
Murray Thompson, 34, from St Albans was last seen by work colleagues on 20 April and his work van was seen later in the Leavesden Road area of Watford.
It was found abandoned in Robin Hood Drive, Bushey, on 4 May.
Forensic investigations have also established Mr Thompson had visited a flat in St Albans Road, Watford.
Det Insp Tim Redfearn said: "Mr Thompson was reported missing over six weeks ago and a thorough investigation has been taking place since.
"Although his body has not been located inquiries have led us to believe he had been murdered."