Police said that a juvenile was also freed, The Independent reported.

Investigators were still unsure what caused the death of James Hughes, 22, whose body was found earlier this week. Hughes was not reported missing until his mother disappeared last week, but neighbors said they had not seen him for weeks.

Heather Wardle was found dead Monday in a patch of underbrush close to her home in Redditch, Worcestershire. She shared the house with Hughes, Brian Kirby, 36, and three younger sons.

Investigators have refused to confirm reports that Hughes's body was in a suitcase concealed in a garden shed.

Hughes reportedly had the mental capacity of a toddler and was unable to care for himself or even to walk for any distance without help.

His biological father said that he used to see Hughes several times a week.

"Although he was 22 James retained the innocence of childhood and he was very, very precious," he said.