Francoise Jansen, 73, said she feared she was going to die after raiders forced their way into her six-bedroom home in Surrey and carried out the attack which police called "appalling" and "horrendous".
Mrs Jansen, who was alone in the house, was forced to open a safe before the men helped themselves to a haul of expensive jewellery and personal items worth a reported £150,000.
Describing the horrific experience, she said: "They asked me if I had any grandchildren, I told them I had 10 and they said, 'We are going to kill you, do you think your grandchildren will miss you?'
"I was consumed by fear. It was sheer hell and all I can remember is praying."
The pensioner said she tried to press a panic button installed in her bedroom, prompting the burglars to boil a kettle and pour scalding water over her arm as punishment.
The criminals, dressed in black clothes and balaclavas, also threatened to cut her fingers off as they held her captive for several hours in the house on a private estate in St George's Hill, Weybridge.
She was gagged, water-boarded and tied to a radiator during the serious assault that left her with multiple injuries. Read More