FOOTAGE from CCTV cameras has played a crucial role in helping detectives piece together the last-known sightings of missing Alice Gross.

As the search for Alice, 14, from Hanwell, goes into its fifth week, detectives are reviewing material from around 300 CCTV cameras.

The material has been gathered from cameras covering a six-mile-square area and a team of 30 is working on this strand of the inquiry.

A range of officers and staff from across the Met are taking part in the ever-expanding search for Alice.

To date, it has involved the underwater and confined space search team, marine support unit, search dogs, air and territorial support Unit, borough officers, volunteer police cadets, visual images identification, plus licensed search officers.

Officers from as far afield as South Wales and West Yorkshire have all provided specialist input to help with the search for Alice.

On Thursday, four weeks on from the last sighting of Alice, during police appeals for information to help find her, the Met received 150 calls.

Det Supt Carl Mehta said: "CCTV is clearly crucial in our investigation, but we still need the public's help.

"Our searches are continuing in the local area today, and there are extra officers involved.

"In more than 30 years of policing, I have never seen such a strong community reaction. Tthis is a community that is totally behind the search to find Alice and bring her home."

There is a £20,000 reward for any information that helps police to find Alice.

Anyone with any information is asked to contact the Incident Room on 020 8358 0100, or call Crimestoppers anonymously on 0800 555 111.