The death of Timothy Veasey at the Wolds prison, North Humberside, was not being treated as supicious, police said.
Veasey, 32, was on remand accused of the murder of Adelaide Ruth Raines, who was stabbed to death at her home at Oak Farm, Broughton, North Yorkshire.
Her handbag was missing when her body was found by her 38-year-old son, Guy.
Police said Mrs Raines, who had been hanging Christmas decorations when she was attacked on 20 December, died from multiple stab wounds.
A Humberside police spokesman said a full investigation would be carried out into the death of Veasey, formerly of Norton, near Malton, North Yorkshire.
"We are purely investigating the death with a view to preparing a file for the coroner," the spokesman said.Reuse content