An air-quality group has called for the company in charge of the Beddington Incinerator to be prosecuted following a fire last month.

Four fire engines and 25 firefighters were involved in putting out a blaze in the site's waste transfer facility on July 11, which took more than nine hours to bring under control.

South West London Air Quality Monitoring Group claims Viridor misled the public by describing the incident only as a "small fire", failing to acknowledge how burning waste materials would have released a range of pollutants into the environment.

Writing to the Environment Agency, which oversees the operation of polluting plants such as the incinerator, Jim Duffy and Dave Tchilingarian said: "In an attempt to minimise the gravity of the fire and keep the public in the dark about it, Viridor's public relations company described the fire as 'small' in their press release, while London Fire Brigade described it as 'serious'.

"This seemed to be more a matter of preserving the company's reputation than providing straightforward information to the public.

"As an air quality monitoring group we are concerned that toxins will certainly have been emitted into the air from nine hours of burning many tonnes of mixed waste.

"This was an open fire, not subject to any filtration so toxic particles would have gone into the air unhindered and undiluted."

In their monthly report, Viridor stated that July 11 did not exceed any pollution limits.

A Viridor spokesperson said: “Viridor is currently carrying out an investigation into the 11 July fire at the Beddington Waste Transfer Station. Viridor understands that the London Fire Brigade is also in the process of carrying out its own investigation.

“Viridor would like to reiterate that the fire was restricted to the waste transfer station and did not impact on the energy recovery facility or landfill area which form part of the larger Viridor Beddington site.

“The waste transfer station is a separately permitted facility which has its own waste and fire procedures in place.

“The site team have increased their observation checks, including with thermal imaging equipment on the material stored in the waste transfer facility and continue to monitor waste during its time in storage.

The cause of the fire has not yet been identified. Viridor suspect it was caused by lithium ion batteries or barbecue coals, the main causes of waste fires across the UK.