A council has defended how it processes plastic waste after one of its own recycling bags was found dumped in an unlicensed landfill in Malaysia.

The discovery was made by environmental campaigner Hugh Fearnley-Whittingstall during filming for a BBC documentary examining the UK's relationship with plastic.

While searching through an illegal site, based 250km north of Kuala Lumpur, the tv presenter came across a recycling bag clearly labelled Braintree District Council.

The bag was found amongst a host of other imported plastics from the UK, which were piled as high as five metres.

The site itself was described as the same size as a large football field.

A spokesman for Braintree Council says it was made aware of the discovery last year and immediately launched an investigation.

However, the authority says it has yet to learn how the bag ended up dumped on an illegal site more than 6,000 miles away.

A spokesman said: "We care deeply about the environment, and so when the producers contacted us to say they found one recycling bag in Malaysia we asked our contractor Viridor to investigate with urgency.

"The design on the single bag found by Hugh’s team showed it was at least four years old. We’re aware that some of the council’s empty used recycling bags have been sent abroad in the past but they were processed through an Environment Agency-accredited and licensed processing facility.

"The material was to become an 'end-of-waste product' which specifies no further onward trading as waste, but rather reprocessed, to produce a pellet or flake, and reused as a recyclable material.

"We’re currently unable to identify the source of the bag but any instances where material sent to an Environment Agency accredited facility may not have been treated as end-of-waste will be investigated by Viridor."

Rubbish with labels of other UK councils and high profile supermarkets were also allegedly found on the same site in Malaysia.

The documentary will air on BBC One at 9pm on Monday, June 10.