Work clearing a festering mountain of rubbish had to be halted after a seam of contaminated waste material was discovered at the bottom of the stack.

The 18,000 tonne trash hill on the former Waste4Fuel site in St. Paul’s Cray, had finally started to be cleared after several years.

The towering heap of rubbish frequently caught fire, with 233 incidents over three years costing the London Fire Brigade £914,000.

At its height the trash hill stood at 12 metres high and 18 metres wide and was described as a “living nightmare” by neighbours, stinking of rotting corpses and infested with rats.

Work clearing the waste mountain had begun on November 1 after Bromley Council brokered a deal in August with the Environment Agency.

Contractors Veolia cleared 16,200 tonnes of waste and it had looked like the cleanup operation would be finished ahead of schedule until this latest setback.

The potentially contaminated waste residues must undertake tests to see if they require a safer, more specific form of disposal.

The amount of residual waste on the site is also under discussion and awaits further physical analysis to quantify the remaining waste.

Councillor Colin Smith, Deputy Leader said, “Although there has indeed been a pause in works in recent weeks following the discovery of technically contaminated waste material in a seam of rubbish towards the bottom of the stack (combusted/melted plastics and heavier based carbon materials), amended plans and special arrangements have now been set in place to dispose of it appropriately.

“We are hopeful that work to remove the phone mast will start in the coming days and operational works regarding the waste could even restart as early as next week.”

It is expected to be fully cleared by the end of April at the current rate of operation, barring unforeseen circumstances.