The Italian government has been urged to end the illicit export of plastic waste to Malaysia after an investigation exposed the environmental and health implications of the country being used as a prime dumping ground for unrecyclable plastic.

Demand for plastic is the second highest in the EU, after Germany, and it is the sixth-largest exporter of plastic waste to Malaysia. Malaysian imports of plastic waste from wealthy countries have risen dramatically since China, previously the world’s biggest importer, imposed a ban in January 2018.

EU law stipulates that member states can export plastic waste to non-EU countries only if it is recyclable, and that recycling companies must adhere to the environmental and technical standards required of treatment facilities in Europe.

But lax controls at ports means a huge amount of contaminated and hard-to-recycle plastic is being shipped out of Europe and ending up in illegal factories.

The investigation by a team of journalists at Greenpeace Italy found that of the 2,880 tonnes of plastic waste Italy exported to Malaysia between January and September last year, almost half was received by companies operating illegally.

Because those firms lack the capacity to deal with contaminated and unrecyclable plastic, much of the waste ends up piled outside their factories, burnt or in landfill.

“The [Italian] government cannot pretend that nothing is happening illegally – it must intervene,” Giuseppe Ungherese, who leads Greenpeace Italy’s pollution campaign, told the Guardian.

“We know that only a small number of containers leaving Italian ports are properly checked. A civilised country cannot close its eyes and dump the problem on a less developed nation – it’s like cleaning the house but hiding the dust under the carpet.”

Greenpeace Italy conducted an undercover investigation of factories that were not among the 64 listed by Malaysian authorities as having permits to recycle plastic waste. The team found evidence of illegally stored plastic (including packaging produced by Italian companies), workers living inside factories and plastic being burned.

Tests carried out on water and soil samples close to mounds of discarded plastic showed an alarming level of contamination, while doctors said that respiratory illnesses had risen in villages hosting illegal factories.

YB Tuan Ng Sze Han, a politician in the Malaysian state of Selangor, told Greenpeace that the contents of shipments arriving in the country rarely corresponded to what had been declared at customs.

“Only about 20 or 30% can be recycled,” he said. “The rest has to be discarded, which causes enormous problems and pollution. Most westerners are unaware of this. They think their countries are doing an excellent job of recycling; too bad it’s not at all like that.”

Similarly to other large European countries, Italy does not have recycling procedures in place to deal with all the plastic the country produces, and so relies on exports.

“We use too much and get rid of the problem by sending it to less developed countries. They only take it because of the economic advantage,” said Pierdavide Pasotti, one of the Greenpeace journalists who worked on the investigation.

Malaysia’s plastics processing industry is worth an estimated £650m. Zuraida Kamaruddin, a Malaysian minister with responsibility for the management of plastic material, told Greenpeace: “If we don’t try to take economic advantage of it, somebody else will.”

The United Nations announced last May that almost all of the world’s countries had agreed, as part of an amendment to the Basel convention, to a deal aimed at restricting shipments of unrecyclable plastic to poorer countries.

From January 2021, exporting countries will have to obtain consent from the governments of countries receiving contaminated, mixed or unrecyclable plastic waste.

Malaysia does not have the legislative tools to ban imports, although it did begin a crackdown last year by closing 140 illegal recycling factories and returning 150 containers full of plastic to 13 countries, including the UK, France, the US and Canada.

The Greenpeace investigation also revealed that since Malaysia began its crackdown, there has been a rise in the number of brokers, mainly in Hong Kong, organising shipments.

“They are simply doing the paperwork,” said Pasotti. “The shipment gets legitimately brokered through Hong Kong while the container from Italy goes straight to Malaysia. It could be that the Italian exporter, aware of the crackdown in Malaysia, is transferring the risk.”

Producers of plastic waste are ultimately responsible for where it ends up, and so long as they receive paperwork certifying that the plastic waste has been recycled, they are legally safe.

Meanwhile, governments have the power to impose bans on exports to countries where they know the system does not meet legal standards.

Greenpeace has given its findings to Italian prosecutors. Paola Ficco, an environmental lawyer, said if a case emerges then all those found to be involved in the illegal trafficking of plastic could face severe penalties.