Olympic chiefs have been criticised for putting people’s health at risk by digging up deadly asbestos at the building site on Leyton Marsh where a massive basketball training hall has been built.

A ground investigation report commissioned by the Olympic Delivery Authority in January said the land - which was used as a dumping ground for World War Two rubble - was contaminated with lead, arsenic and possibly asbestos.

The report recommended workers wore protective clothing, however the Olympic Delivery Authority (ODA) have admitted this did not happen when work started on the site behind the ice bridge in Lea Bridge Road two months later.

In conjunction with the Health and Safety Executive, the ODA also decided not to carry any air sampling monitoring to see if asbestos fibres were present in the air.

When asbestos fibres are breathed in, they can get trapped in the lungs and lead to serious health problems like lung cancer.

The contaminated rubble was not removed off site but sat uncovered in mounds, exposed to heavy rain.

Although work began on site on March 5, asbestos was only formally identified nearly four weeks later on March 30 after concerned residents alerted British Waterways.

A BW environmental scientist concerned about lead leaching into the River Lea just yards away, in turn contacted the Environment Agency which carried out the tests identifying the harmful substance in the uncovered mounds.

Two days after the EA visit, some the rubble was covered over with tarpaulin sheets. Some of it still remains exposed to the elements.

A spokesman for the Environment Agency (EA) said safety on the site was the responsibility for Waltham Forest Council, but the general advice the EA give out is if you suspect asbestos is there then “don’t dig it up.”

“It’s only if you break it up into little fibres and breathe them in it does damage,” he said, adding that the EA believed there was no risk to the River Lee nearby.

Leabridge ward Cllr Ian Rathbone said: “I do find ironic that an organisation that is supposed to be about health and fitness is playing fast and loose with the health and fitness of our local residents.

“Most definitely it’s putting people’s health at risk, we can’t know how much asbestos is there simply because no one has bothered to go and measure it.

“But for at least three weeks all those mounds have been there blowing off into the river and into people’s houses in Riverside Close just opposite,” he added.

An ODA spokesman said health and safety was their “number one priority.”

“Our work at Leyton Marsh is subject to the same high standards we adhered to during the construction of venues on the Olympic Park and elsewhere,” he added.

“As is routine when working on a site where small amounts of material might be present, our park health team carried out asbestos-awareness briefings for the workforce,” he added.

A spokesman for Waltham Forest Council said the site was not their responsibility, but that of the land owner, the Lea Valley Regional Park Authority (LVRPA) – despite local authorities being responsible for the enforcement of health and safety on construction sites.

A spokeswoman for the LVRPA declined to comment.

A decision has still not been made what to do with the contaminated rubble.

The site has been a bone of contention for hundreds of residents who opposed the plans since they came to light.

Many people blocked lorries accessing the site, along with anti capitalist Occupy protesters until the ODA obtained a High Court injunction.