A GARDEN waste blaze which has burned near York since before the New Year was caused by spontaneous combustion, an investigation has concluded.

The fire at Harewood Whin, Rufforth, began on Monday December 29, sending a plume of smoke towards York on the prevailing westerly winds.

A spokesman for site operator Yorwaste said its investigation had now revealed that the fire started as a result of the spontaneous combustion of compost.

He said a contributing factor had been a temperature drop caused by a heavy frost which 'provided moisture to the material'.

He added: "We are now reviewing our procedures to minimise the risk of this happening again in the future. The fire continues to burn under a controlled environment with daily inspections from the fire service and we remain in direct contact with the Environment Agency."

Yorwaste has claimed previously that no toxic fumes had been released by the fire and said it was doing everything in its power to deal with the matter in the most efficient and safe manner.

However, Public Health England has warned that chemicals in the smoke could worsen existing respiratory conditions, such as asthma, and advised residents in affected areas to keep doors and windows closed as much as possible to limit any exposure.

And a Poppleton resident has repeatedly claimed that toxins in the smoke had been making his family ill, and he called on Friday for inert materials to be used to suffocate the fire rather than allowing it to burn itself out.

"If I started a bonfire in my garden, accidentally or otherwise, and it was affecting my neighbours, I would be forced to put it out within days if not hours," added the man, who did not wish to be identified.

York Outer MP Julian Sturdy said he was given a briefing about the fire on Friday afternoon by an Environment Agency official, who had assured him the blaze had been isolated and would not spread.

He was told that fire service managers felt suffocating the fire could make matters worse. He was also told steps would be taken to ensure garden waste was processed more quickly when dumped in future, and the temperature monitored more effectively, to ensure there was no future repeat of the blaze.