Toni-Ann's mother has been traced in Jamaica

Toni-Ann Byfield and her father Bertram, 41, were found in a bedsit in Kensal Green on Sunday, after neighbours reported hearing shots and a scream.

Police believe the girl, who was shot in the back, saw her father being gunned down and was killed to stop her identifying the gunman.

On Wednesday, Metropolitan Police Commissioner Sir John Stevens said that, if it was necessary, any witnesses whose evidence may lead to a conviction could be removed from London and even taken abroad in order to protect them.

He said: "I give my word on that".

According to Sir John, police are "already getting good co-operation from the local community in north London" over the shooting which has appalled him.

Toni-Ann was only staying with her father for the weekend

"I was appalled by the brutality of it - to think a seven-year-old was trying to get away is just absolutely appalling.

"You just have to wonder at the level of violence going through the mind of the person to pull the trigger, I was appalled and I have been in the business a long time".

Toni-Ann was a ward of court, who had been known to Birmingham Social Services since the end of November 2002, and had been staying with her father, a convicted criminal, for the weekend.

An inquiry into social services' actions, which was responsible for her care, is under way.

Man in custody

Toni-Ann's mother, Christine Richards, has been traced in Jamaica and told of her daughter's death.

The seven-year-old arrived in the UK from Jamaica in June 2000 and stayed with relatives in Birmingham.

She was due to start primary school this week.

A 23-year-old man arrested on Monday night in connection with the incident has been bailed until October pending further inquiries.

He remains in custody at a north London police station in connection with suspected immigration offences, a Scotland Yard spokesman said.

Anyone with information about the shooting is asked to call police on 020 8358 0608.