The arrests come over a year after the prosecutor's office in the port city of Durres opened investigations into more than 100 containers of hazardous waste, which allegedly came from a Turkish-owned steel mill in Elbasan.

Earlier, prosecutors told AFP that 33 arrest warrants had been issued over a suspected toxic-waste trafficking network, including customs agents and employees of the National Environment Agency.

"This was not a single crime but a series of illegal actions with serious impacts on the environment, health, customs ... and fair business practices," a prosecutor's office statement said on Wednesday.

The alleged offences include the trafficking of prohibited goods, abuse of office and money laundering.

Police said they were still searching for 13 other suspects, including three Turkish nationals and one German.

Officers launched raids on Tuesday after lab analysis confirmed the materials, returned to Albania in 2024, were toxic, said prosecutors.

Customs documents said the shipment carried iron oxide when it left the Balkan nation for Thailand.

But the shipment was rejected after an environmental group claimed it contained illegal toxic waste instead, forcing its return to Albania.

- 'Dangerous and toxic' -

Analysis of waste samples, including material originating from the Turkish-owned Kurum International steel plant and two Albanian firms, found it to be "dangerous and toxic" dust from an "electric arc furnace", the prosecutor's office said in a statement.

The samples also contained material posing a particular risk to the marine environment.

The finding confirms the claim by the environmental group Basel Action Network, which prompted the shipment's return.

"Kurum International was fully aware of national and international waste regulations," the prosecutors said.

Among the suspects are five Kurum International managers, an administrator and an accountant.

The 102 containers, seized in November 2024, are now securely stored at a port near Durres, the statement said.

Experts in Albania began taking samples from the shipment last October as part of an investigation into the smuggling of prohibited goods.

At the time, prosecutors said they had opened an investigation into suspected smuggling and abuse of office in cooperation with the European Anti-Fraud Office.

BAN founder Jim Puckett said it was unclear why the sample had taken so long to be analysed and warned the material could have leaked or been tampered with in the meantime.

The prosecutors argued that the Albanian authorities lacked the facilities to analyse the waste, so samples were eventually sent to an Italian lab.

According to environmental campaigners, industrial waste is often shipped by Western countries to be processed in Asia and Africa, a global trade they estimate may be worth up to $82 billion a year.