Council officials in Alblasserdam have forcibly closed two houses in connection with an investigation into a bungled kidnapping linked to a drugs raid.

A 56-year-old man from Hoofddorp was abducted in the nearby village of Cruquius more than a week ago in what police say was a case of mistaken identity. He was released more than 50km away in Delft last Wednesday, suffering from injuries.

Two hours later police arrested six people from Gouda in connection with the kidnapping. Shortly afterwards a man from Alblasserdam told police he believed he was the intended target.

Investigators say the episode appears to be linked to the interception of a 1,899 kg cocaine shipment in Antwerp, which arrived from Ecuador on July 28.

The house of the man from Alblasserdam was seized by police last week to prevent reprisals. A business premises belonging to him was burned down last Friday, two days after a previous attempt to set it on fire failed.

On Monday night another house in the town, which lies 20km south-east of Rotterdam, was also seized by the council. RTV Rijnmond said the people living in the two houses were known to each other.

Police are also investigating another suspicious fire at a commercial address in Zwijndrecht on Friday night, which they believe may be related to the kidnapping, but so far they have been unable to establish a link. In both incidents a car was driven into the facade of the building and set alight.