The device was discovered this morning at the site in Leyton. It has now been defused safely.
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.”
Work started this month on construction of the practice courts and is due to be completed by the end of May.