The body of a badly burned woman found in an Oxfordshire field has been identified as a 94-year-old Londoner.
Mrs Zaudy had lived alone since the death of her husband in the 1960s
Mrs Thea Zaudy, from Notting Hill Gate, was found by a farm worker in Milton Common, west of Thame, on 13 July.
Thames Valley Police said a 23-year-old man, from London, was arrested on Thursday on suspicion of murder.
Two women, aged 19 and 41, and a 38-year-old man, also from London, were arrested earlier and currently remain in custody.
Her burned body was found next to a suitcase, thought to have been used to transport the body, a police spokesman said.
He added that she had been set on fire after death and witnesses had reported seeing a fire in the fields the night before she was found.
Detectives said the 38-year-old man and the 41-year-old woman were being held on suspicion of murder.
The younger woman has been detained on suspicion of conspiracy to murder.
Mrs Zaudy, who was a British citizen, had lived alone since the death of her husband in the 1960s. The couple did not have any children.