A GWENT teenager was found dead at her home on Friday by her distraught mother.

Shocked neighbours in Pentre Close, Coed Eva, Cwmbran, said they believed 14-year-old Alex Mitchell died of carbon monoxide poisoning, and now police and the Health and Safety Executive have launched an investigation.

The Fairwater High School pupil was discovered in her bed by her mother, Anne Mitchell, on Good Friday, when she came home from work.

It is also understood the family's pet dog was found dead downstairs.

Flowers and soft toys, along with messages of condolence, have been left in the front garden of the house by grieving friends.

Natalie Aston, who lives two doors down from the Mitchells' house, was alerted by Mrs Mitchell's cries on Friday afternoon.

Mrs Aston, and two other neighbours, went into the house with Mrs Mitchell, who is currently staying with relatives.

"We saw Alex in the bedroom - it was very traumatic," she said. "I spoke to the emergency services, and they advised us to attempt resuscitation, but I could see it was too late," added the 42-year-old mother of four.

"I can't believe what she must be going through - this has totally shocked us all."

It is understood the mother and daughter had recently moved into the house.

Fellow neighbour Emma Turner is helping to organise a collection in the street for a wreath.

She said: "I came home from work about 4.30pm, and saw the emergency services.

"All the windows were open and I presumed there had been a fire. "I heard Alex's mother came home and found the dog first of all. "Not many people knew them - they just kept themselves to themselves. It's just so tragic."

Police officers remained at the house until Monday morning. A police spokeswoman said the coroner's office had been informed. She said officers had launched a joint investigation with the HSE "into the circumstances surrounding the death of a 14-year-old female".

A spokesman for the HSE confirmed an investigation is under way. Deputy head of Fairwater High Lynne Fear said the news was "just awful". She said: "All the staff are shocked and saddened by the news. She was a lovely girl, and this is a very sad situation."

Mrs Fear said pupils and staff would be holding a special service in Alex's memory when the school re-opens on April 11.