Police have named the man as Thomas Baird. He'd been stabbed and was pronounced dead in the early hours of Saturday after the blaze at his home in Westerdale, Hemel Hempstead, Hertfordshire.
A post-mortem examination carried out yesterday concluded that the 63-year-old died of trauma to the head and neck, and stab wounds to the chest.
A 30-year-old man from Hemel Hempstead, who was arrested on suspicion of murder on Saturday, remains in police custody.
More top news
The rogue green-fingered fanatic has been secretly hacking shrubs at parks and doing a "proper" job.
Labour MP Kate Hoey is asking the National Audit Office and the Commons' Public Accounts committee to examine the £175m project.
The group, which also includes Shepperton Studios, has made more than 2,000 films and 800 TV shows over the last 80 years.