Concerns were raised after an unexploded bomb was found at an Olympics venue ten years ago this week.
A bomb from the Second World War was unearthed at the building site for an Olympics training venue.
The device was discovered behind the Lee Valley Ice Centre in Lea Bridge Road, Leyton, at around 10am on Wednesday, March 14.
Construction teams are currently building a temporary basketball hall there which will be used for training by athletes during the Games later this summer.
The bomb has now been made safe and removed.
A Met spokesman said: "Police were called to Leyton Marshes to reports of a suspected unexploded World War 2 bomb being discovered at the site.
"The area was cordoned of and the site evacuated as a precaution, whilst EOD (Explosive Ordnance Disposal) officers made the bomb safe."
Katy Andrews, of the Save Leyton Marshes campaign group, said the apparent discovery raised questions about the amount of preparation that had gone into the bid to build the temporary building.
She said: "We've been told there was a site survey for contamination before work began, but how thorough was it if they didn't spot this?
"This survey wasn't submitted as part of the planning application to Waltham Forest Council either.
"Residents are worried and wondering what else could be there that hasn't been discovered yet."
A spokesman for the Olympic Delivery Authority said: “A small Second World War incendiary device, weighing around a kilogram, was safely removed this morning from the site of a temporary Games-time basketball training venue on Leyton Marsh.
"A routine scan of the site in early February detected metal underground and because of this, an ordnance expert was appointed to oversee the start of works.
"Police were immediately contacted after the device was discovered and it was later removed by specialist officers.
"At no time were nearby people or property put at risk and work has now resumed on site.”
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here