Bulgarian police and investigators joined an international operation run by the European Public Prosecutor's Office against a gang that sold more than 1 million used mobile phones as new. Police searched addresses and premises linked to the case in Bulgaria.

On the Bulgarian side, the economic police and investigation departments of the National Police Directorate worked with the National Investigation Service. They seized documents, electronic devices and other material to help crack the case.

The European Public Prosecutor's Office in Cologne, Germany, is leading the investigation, called "Troja". It started after a tip-off from OLAF, the EU's anti-fraud office.

Police raided addresses at the same time in 19 countries, carrying out more than 160 searches and seizures. They arrested seven people, including two said to be the group's leaders. Police, tax and customs officers all took part.

Workers in Hong Kong and the United Arab Emirates assembled handsets from old phone parts. The phones were then packaged as new devices and shipped to the Netherlands, then on to warehouses in Germany, before being sold online to customers across the EU.

The losses to EU consumers add up to at least 300 million euros. Several member states also lost more than 30 million euros in unpaid VAT.

Investigators found the phones were sold through companies registered in several European countries, including Bulgaria, so the group could use the margin taxation scheme. This let them wrongly cut the VAT they owed, the investigation shows.

Bulgarian police are still helping the European Public Prosecutor's Office and partner agencies with the international investigation.