Officers searched the area for forensic evidence

Detectives said they were keeping an open mind about the circumstances surrounding the deaths of the pair, who were discovered at the property on Harrow Road, Kensal Green, at 0030 BST on Sunday.

Both had bullet wounds and were taken to hospital where they later died.

Operation Trident officers, who investigate gun crime in the black community, have taken over the investigation.

They do not yet know why the pair were killed, but suicide has been ruled out.

Forensic search

Two witnesses who were walking up the road just before midnight have said they heard three or four shots.

Post-mortem examinations showed the girl died from a single gunshot wound, while her father died of multiple gunshot wounds.

Detective Chief Inspector Richard Freeman said: "We have to keep an open mind as the inquiry is at a very early stage.

"Clearly this is a very serious incident, particularly with the death of a seven-year-old child, but undue speculation is unhelpful at this early stage.

"We have not ruled out any line of inquiry - crime, domestic, or any other motive. It is simply too early to say why this tragedy occurred."

Police information hotline 020 8358 0608

Police cordoned off the area, just west of Kensal Green Station, while they searched for forensic evidence.

Traffic was diverted and the property taped up.

One neighbour, who did not wish to be named, said she had always thought of the area as safe.

She said: "I've lived here for two years and there has been trouble but it's never affected me."

The victims have not been formally identified and police have been unable to contact their family, including the girl's mother.

Over the summer police have been working with the community to rid the area of gun-related crime and there have been no Trident deaths for the past three months.

Police have asked anyone with information to contact a special hotline - 020 8358 0608.