Detectives trying to find a “devoted father” who went missing in January have found traces of his blood at the garage where he worked.
They have arrested a 48-year-old man from Brighton on suspicion of murder but issued a fresh plea for help.
Officers had been working on a missing person inquiry after the disappearance of Gary Hampson, 42, three months ago.
But the case has become a murder investigation after blood was found at Kop Cars Body Shop on the border of Brighton and Hove.
Detective Inspector Phil Mays, of the Sussex Police Major Crime Branch, said: “Following extensive forensic examinations of the garage where Gary worked in Little Western Street, Brighton, blood was found at the premises and confirmed through DNA testing to be Gary’s.
“Detectives are now treating this as a murder investigation.
“This is an extremely difficult time for Gary’s family and friends.
“Specialist officers are continuing to offer support to his family both locally and in Liverpool after Gary’s mother and sister were traced following a media appeal in the Merseyside area.”
Mr Hampson, of Old Shoreham Road, Portslade, was last seen when he dropped his daughter home having picked her up from school on Thursday 6 January.
He hasn’t been seen since despite hopes among his family and friends that he might make contact last Tuesday (5 April) for his daughter’s 10th birthday.
His phone was switched off, possibly when the battery died, a few days after he disappeared.
When police issued an appeal for information last week Detective Chief Inspector Jeff Riley said: “Gary is a devoted dad and saw his daughter three times a week without fail.
“Gary said he was going to Liverpool the next day, Friday 7 January, but he hasn’t been seen or heard from since.
“It’s as if he’s vanished without a trace.
“For friends and family not to hear anything from him is completely out of character and they are extremely concerned for his safety.”
Detective Inspector Mays said: “Detectives have made thorough inquiries to piece together Gary’s movements after he said goodbye to his daughter that Thursday afternoon.
“Gary’s family and friends know him as a devoted father and a well-liked local character.
“It is extremely difficult for them not to know what has happened to Gary.
“I’d urge anyone who might have any information, however insignificant it might seem, to please get in touch.
“It might be the crucial information we need to find Gary.”
Mr Hampson has connections not only to Liverpool but also to the St Helens area of Merseyside.
He travelled frequently to Liverpool by car but police have yet to confirm whether he made the journey as planned on Friday 7 January.
Mr Hampson is described as white, 5ft 9in tall, of stocky build, with blue eyes, short dark brown hair and has a Liverpool accent.
The 48-year-old suspect is currently in custody awaiting interview.
Anyone with information is asked to contact Sussex Police on 0845 6070999 or to call the independent charity Crimestoppers anonymously on 0800 555111.
