Mystery surrounds the grisly find of human body parts and organs in shipping containers sent from the UK to Sri Lanka.
The remains were disguised as recyclable materials in more than 100 huge containers.
But now authorities in Sri Lanka want to send the metal shipments back to the UK.
Workers at the port of Colombo were first disturbed by a "strong smell" and later made the sickening discovery alongside mattresses, plastics and clinical waste.
Defra is now investigating in the UK alongside officials in the Asian country.
"We are committed to tackling illegal waste exports, which is why individuals found to be exporting incorrectly described waste can face a two year jail term or an unlimited fine," a Defra spokeswoman said.
"We are yet to receive a formal request from the Sri Lankan authorities, but Defra has contacted them directly to find out more information."
A spokesman for Sri Lanka’s Central Environment Authority said: "The waste material brought to the country under the guise of mattresses from the UK is extremely hazardous."
Disguising human remains as recyclable metals can be highly lucrative as it is illegal to export "anatomical waste", British waste disposal experts said.
Every year, British households throw 22 million tonnes of waste into the bin.
However, Britain does not have the requisite infrastructure to recycle its own waste, so it is sent abroad.
But some countries say they are now deluged with other nation's rubbish and Malaysia is set to return 3,000 metric tonnes of waste to its country of origin.
