Demolition of a former Sainsbury's depot was given the all-clear last month following concerns about a possible unexploded bomb on site.

Developer Panattoni could not knock any buildings down at the site in Elstree Way, Borehamwood, until an unexploded ordnance threat assessment had been carried out.

Hertsmere Borough Council had attached the planning condition because it had reason to believe a bomb was dropped in the vicinity of the site during World War Two.

During the war, the site predominantly comprised of film studio MGM buildings and open fields.

The rural district of Elstree sustained an overall low density of bombing with an average of 28.3 items dropped per 1,000 acres, according to figures by the Home Office and London Bomb Cencus Mapping.

Records suggest that one bomb was dropped on one of the large stage buildings in the south of the Elstree Way site.

Leading UK EOD company 1st Line Defence were commissioned to assess the site and it concluded the site is not considered to be "homogenous" and the majority of the site has been assessed as "low-risk".

Although the risk has been identified as "low", it does not mean there is no risk of finding an unexploded ordnance.

Unexploded bombs do not spontaneously explode. All high explosive filling requires significant energy to create the conditions for detonation to occur.

Demolition on the site is underway. Panattoni is turning the depot into several industrial units with the first phase of buildings available from the end of 2020.