Mrs Routley, 34, was located 'safe and well' in a hospital after a nationwide hunt.
She disappeared from her bungalow near Taunton, Somerset, on 28 September and police feared that she might have been kidnapped or murdered.
But on Friday night she was traced to a hospital in the North of England after nursing staff recognised her picture in a television news bulletin.
Avon and Somerset police confirmed that she had been found and had left home of her own accord, but Superintendent Peter Hinde, the detective who headed the intensive search for her, said she would not say why she went missing or where she had been.
She also flatly refused to speak to any members of her family, including her husband, Brian, 40, her daughter, Alexis, 11, or her mother, Eileen Feilen, of Taunton.
Superintendent Hinde could not confirm that Mrs Routley was still in the hospital or that she was being treated for a drugs overdose.
Mr Hinde said he was extremely frustrated over her stance and the many unanswered questions. He did not expect her to be prosecuted for wasting police time.
'The good side is that we have traced her alive and well,' he said.
Mrs Routley's husband, a marine upholsterer, said he was baffled. In a brief statement to reporters, he said, close to tears: 'Please come back Allie.' He had 'absolutely no idea' why his wife went off.
More than 50 police were involved in the search for Mrs Routley, who was last seen driving her daughter to catch a school bus in the nearby village of Fitzhead on 28 September. Her car was later found burnt out, and there were signs of disturbance at the family home.Reuse content