A jewellery designer whose body was found in his burning home in a village had been viciously attacked before his death, detectives said.
Michael Griffiths, 59, had serious injuries to his head and body when he was found by firefighters on Thursday morning.
A murder inquiry has been launched by detectives who fear he may have been targeted because of his work as a jewellery designer, and because of his dealings with antiques.
It is understood that ''well-known and popular'' Mr Griffiths lived alone at the house in Old Glebe in Fernhurst, West Sussex, and no-one else was in the property at the time.
A post-mortem examination carried out yesterday by a Home Office pathologist failed to establish a cause of death and further tests are now being carried out.
As police appealed for information, investigators said a suspicious seat of fire was found near a window in the lounge at the back of his building.
Detectives from the Surrey and Sussex major crime team also said a couple of windows appeared to have been opened before the fire broke out.
Detective Chief Inspector Jeff Riley, who is leading the inquiry, said: ''On Thursday evening, fire investigators advised us that they were suspicious of a seat of fire close to a lounge window at the rear of the house.
''Smoke patterns on a couple of the windows suggest that they were open when the fire broke out.
''The post-mortem has revealed that Mr Griffiths suffered serious injuries to his head and body, but at this stage it is not possible to firmly conclude that they were the cause of his death.
''Tests are now being carried out to establish how he died.
''Michael was a well-known and popular local man who was a talented jewellery designer and maker and was an enthusiastic antiques buyer and seller.
''I am considering that this may have led to him, or at least his home, being specifically targeted and this forms one of our main lines of inquiry at this time.
''There is no doubt that we are dealing with a murder and I would appeal to everyone in Fernhurst's close-knit community to think about anything suspicious or just out of the ordinary in the days leading up to the fire and especially the time between 6.30 and 8am on Thursday morning, to give us a call.''
It emerged that Mr Griffiths was visited by callers at about 8.25pm on Tuesday and they threw snowballs when he answered from an upstairs window.
Mr Riley said: ''This may well have been an innocent prank, but we would also like to hear from them or anyone else who experienced a similar thing.''
Scenes of crime officers and forensic investigators were examining the house and are expected to remain at the scene for a few days.
Their work was being hampered by fire damage, with some of the upstairs area needing to be made safe before their investigations can continue.
Appealing for information, Mr Riley added: ''Someone, somewhere has vital information that will lead us to Michael's killer. Please call.''
Anyone with information is asked to call Sussex Police on 101, quoting Operation Killick, or Crimestoppers anonymously on 0800 555 111.