‘We had the doctors come out and tell us everything they did [for the survivor] – and it wasn’t our daughter,’ said Mr Campbell, 56.

When doctors allowed the couple in at 2am to see the patient, they were horrified to discover their recovering patient was Karen.

Mr Campbell said: ‘I said, “That’s not my daughter, that’s Karen! Where’s my daughter?” The doctors were as shocked as we were.’

An hour later, a police detective arrived and showed them a picture of their daughter, a steakhouse restaurant manager from Medford, Massachusetts.