German special police have arrested several people suspected of carrying out an old-fashioned heist of a €4m (£3.6m) 100kg gold coin in Berlin.

“We are conducting searches and executing arrest warrants in several places in Berlin concerning the break-in at the Bode Museum in March,” regional police said on Wednesday.

A spokesperson confirmed newspaper reports that the suspects arrested at two properties in the Neukölln district were members of an “Arabic-Kurdish clan” known to investigators in connection with drug smuggling, arms trading and racketeering.

The Berlin state office of criminal investigations tracked down the suspects through DNA evidence.

The theft of the Canadian commemorative coin stunned Berliners due to the seeming simplicity of the robbers’ plan.

Masked police guard a house in Berlin on Wednesday after raids on several properties in connection with the gold coin heist. Photograph: Paul Zinken/AP

At least two thieves entered the museum through a third-floor window in the early hours of the morning by propping up a ladder on the elevated tracks of the railway between Hackescher Markt and Friedrichstrasse stations.

They then smashed through the bulletproof cabinet, possibly with a sledgehammer, and made their way back via the same route with the heavy coin in tow – all without being noticed by security personnel or activating the alarm.

Once outside the museum, the thieves used a wheelbarrow to push their loot 100 metres down the tracks and across a bridge over the river to nearby Monbijou Park, where they dropped and most likely damaged the coin while abseiling to the ground.

With a diameter of 53cm and 3cm thick, the Big Maple Leaf coin is one of only five pure gold commemorative pieces issued by the Royal Canadian Mint in 2007.

Its whereabouts remains unclear. Police suspect the robbers may have melted the coin down at the earliest opportunity.

“The trick used by such criminals is that they add, for example, a little bit of copper to the molten gold in order to change the purity levels and cover their tracks,” an investigator told Die Welt newspaper.