Detectives released a man and youth on Friday held on suspicion of murder after the discovery of the body of missing disabled man James Hughes.
Hughes, who had the mental age of an 18-month-old child, was found dead at the family home in Redditch, Worcestershire, on Wednesday. Police on Friday said dental records confirmed his identity.
They declined to comment on media reports that his body was found in a suitcase hidden in a shed.
"It is still not known how and when James died," said Superintendent Jane Horwood of West Mercia Constabulary.
"A post-mortem has proved inconclusive and police are awaiting the results of further tests. These are likely to take some weeks."
Police said a man and a youth arrested by detectives on Wednesday were released without charge.
Hughes and his mother Heather Wardle, 39, were both reported missing on Saturday from their home.
Wardle, who left home last Friday saying she was going to visit a friend nearby but never arrived, was discovered dead at the base of a tree with a ligature around her neck on Monday night.
Her death is being treated as "unexplained".
Hughes, whose 22nd birthday was on Sunday, suffered from epilepsy, usually used a wheelchair and required constant care.
His father Paul paid tribute to his "beloved" son in a statement released on Friday.
"My son was the most beautiful of Mother Earth's creations that I have had the privilege to meet. His aura of happiness and mischief was plain for all to see," the statement said.
"Although he was 22 James retained the innocence of childhood and he was very, very precious. He was irreplaceable and it's left a massive hole in my life."
