Dutch authorities have taken part in an operation to dismantle a criminal operation responsible for smuggling 35 tonnes of cocaine through Rotterdam, Antwerp and Hamburg.

Six people were arrested and 24 house searches were carried out in an operation led by German police and customs and supported by Europol. The house searches took place in Cologne and Hamburg on May 31 and June 5 respectively.

Law enforcement agencies from Belgium, Ecuador and Columbia were also involved in the investigation, which began in April last year.

Europol said the network was based in Germany and shipped around 35 tonnes of cocaine from Columbia, Ecuador, Suriname, Guyana and Paraguay.

The shipments were mainly routed through Hamburg in what German authorities described as the biggest cocaine seizure in the country’s history.

The investigation also linked the gang to another potential supply route from West Africa, Europol said.

Items including luxury cars, jewellery, electronic equipment and cash were seized during the house searches.

Europol said the operation was part of a wider effort to co-ordinate enforcement across EU member states to target multinational criminal networks “with close ties to the command-and-control centres affecting the EU’s internal security”.