e-Waste from the UK has been illegally dumped abroad including in Ghana and Nigeria, says the Environmental Investigation Agency (EIA).

Environment Waste Controls (EWC), which is based in Merseyside and is used by UK firms including ASDA, Tesco, the NHS and Network Rail, admitted that electrical goods that should have been disposed off from its ended up in Ghana, after being sold to a third party.

EWC's admission follows an investigation by the EIA, which saw tracking devices placed within broken TVs, in a bid to identify where they ended up. The investigation, which is the subject of an episode of the BBC's Panorama programme, due to be broadcast tonight, revealed the devices said had not been tested before leaving the UK, despite this being illegal under the Waste Electrical and Electronic (WEEE) Resources Regulations 2006.

"This is unacceptable and EWC has put in place measures to prevent a reoccurrence of this practice and to undertake a full investigation in cooperation with the regulator and relevant authorities," the company said in a statement.

"We have instructed all our sub contractors that no electronic equipment deposited at designated collection facilities operated by EWC should leave the UK until further notice."

Panorama Track My Trash estimates that more than three-quarters (77 percent) of illegally exported e-Waste from the UK ends up in Ghana and Nigeria. It is thought the UK produces around one million tonnes of e-waste every year.