Olympic chiefs broken planning law by excavating public land deeper than permitted to build a giant basketball court. And now they are taking protestors blockading the site, who include anti-capitalist splinter group Occupy, to court.

Instead of the 15cm Waltham Forest Council allowed The Olympic Delivery Authority (ODA) to dig, they have gone as far down as 50cm to lay foundations for the 12m-high training facility on Leyton Marshes, behind the ice rink in Lea Bridge Road.

The land is just over Hackney’s border with Waltham Forest, but is used by hundreds of residents who use it as a recreational facility and who say it will ruin views across the River Lea from their homes.

Waltham Forest planner Ian Ansell said they were looking into whether the extra depth was a material amendment, whether it raised any land contamination concerns, and whether it affected any archaeological interests.

“My personal view is that if these matters are adequately resolved, I do not consider that the additional soil removal has any substantive amenity impact,” he said.

But Leabridge ward Cllr Ian Rathbone called for work to be stopped while investigations took place to see how far the ODA have departed from the plans they submitted to Waltham Forest.

“How can it be non-material to change from an 8 inches deep skimming of topsoil, to removing nearly 2 feet of rubble?” he asked.

“They’ve broken the law, and they realise they’ve got caught out, I just think they are rude and arrogant walking over local people.”

For two weeks direct action campaigners from the borough have been blocking lorries entering the site, and protestors from anti-capitalist movement Occupy joined them last week.

The peaceful protesters caused controversy last year when they set up camp around St Paul’s Cathedral, and were evicted.

Opponents are angry at the way they claim planning permission was pushed through by Waltham Forest Council last month, and are not convinced the development will not stay once the Olympics are over – especially now the ODA has admitted the foundations run deeper than permitted.

Work was halted for over a week - but on Tuesday an injunction was served by the ODA on “persons unknown” for “unlawfully occupying land owned by Lee Valley Regional Park Authority in connection with protest activity.”

They are claiming more than �335,000 in damages and costs and went to court this morning.

“This in our view an attempt to silence people who have very valid questions about their environment,” said Leabridge ward Cllrs Ian Rathbone and Deniz Oguzkanli in a joint statement.

“It would be interesting to see if local people sued they would have a counter claim for loss of amenity and irreversible loss of wildlife in an inner city area.”

An ODA spokesman said deeping digger did not change the principles behind the original planning consent: “Inevitably site surveys can only provide a snapshot of ground conditions and it is often the case, as in our work at Leyton Marsh, that initial digging reveals different soil and sub-surface composition that makes it necessary to go a little deeper to provide stable foundations,” he said.

“The ODA alerted the local authority as soon as we became aware that this would be necessary and submitted an amended application, as is standard practice.

“This is a temporary structure that will be removed as soon as the Games are finished and land returned to its previous state.”