The grieving parents of a young girl murdered in an arson attack on the family home described today how their "innocent angel" sought to escape the flames by hiding under the blankets of her bed.

Francesca Bimpson, 3, suffered appalling burns in the fire at the semi-detached house in Everton, Liverpool, that she shared with her parents, older brother and two sisters. She lost her fight for life three weeks later on the day before Christmas Eve.

Detectives have yet to establish why somebody would have deliberately poured petrol through the front door letterbox, igniting an inferno in the front hall and staircase and cutting off the line of escape for the sleeping family upstairs.

Kieron Bimpson and Eleanor Skelhorne, the child's parents, wept as they spoke publically for the first time about their "gorgeous little girl" and made a public appeal for help to catch the arsonist.

Mr Bimpson, 36, said: "Someone must know that the person responsible has robbed the world of an innocent angel. This is such an evil crime. They must have known there were children in the house and they did not care. They put Francesca through torture. This was an attempted murder of the whole family, and tragically one of us has died."

Police remain puzzled why Mr Bimpson or his family were targeted. Officers described the couple as decent and hard working. Mr Bimpson, a martial arts expert, works for a charity that helps to rehabilitate young offenders and problem teenagers.

Mr Bimpson described how earlier on December 2 the children had been talking excitedly about Christmas. They had been on an expedition to Asda to buy a Christmas tree which was immediately put up in the living room at Francesca's insistence.

"Francesca was only three years old and was very excited," said her father. "She was looking through catalogues and was saying, 'I want this, I want that' just like any other child that age. It was a lovely night. Everybody was so excited and looking forward to Christmas.

"I was excited myself because as I put up the Christmas tree I was thinking about what the children's faces would look like on Christmas day."

The family, including Francesca's sisters Christina, 8, and 17-month-old sister Anne Marie and brother Kieron, 14, were all asleep when they woke to choking, black smoke around midnight. Francesca, described by Mr Bimpson as a "daddy's girl" so timid she would cling to him, remained trapped in her bedroom.

"I remember it being about midnight and there being suffocating black smoke and me gasping for air. We opened a bedroom window to try to breathe. We tried to get Anne Marie out of the window. Eleanor was screaming and the whole staircase was on fire. We were shouting 'Help, get the kids'. "

Mr Bimpson jumped out of the window on to a roof, breaking his ankle and a heel in the process. He managed to persuade Christina to jump from her bedroom into his arms but Francesca, also at the window, appeared overwhelmed and fled to the seeming safety of her bed.

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