A live grenade recovered from outside a block of flats may have been left as a warning to a local fruit and veg trader.

The device in Kerkdriel was made safe by the explosives disposal team (EOD) on Monday morning. Brabants Dagblad initially said the mayor of Maasdriel, Henny van Kooten, who lives in the building, was the likely target because of his pro-active stance on organised crime.

RTL Nieuws later reported that police were investigating the possibility that the real target was the son of the owner of a local fruit import business whose trade routes were used by drug smugglers.

Dozens of neighbouring homes were evacuated and shops in the area were closed while police, fire crews and explosives experts dealt with the incident. A spokesman for the regional safety board in Gelderland-Zuid said extra precautions were taken because the protective cover had been removed from the grenade, making it active.

Several containers loaded with drugs from South America have been intercepted on their way to the De Groot family firm in recent months, costing gangsters millions of euros in lost contraband.

Graffiti including the house number of the owner’s son was found on a wall near the spot where the grenade was placed.

Taco van der Dussen, a lawyer acting for the family, said the family had been aware of tensions for some time and was stepping up its private security. ‘We don’t know the details, but we’re not ruling out this being directed at us,’ he said. ‘This hasn’t come out of the blue. It’s a very tough situation and worrying for the family.’

Van Kooten, who has a flat in the block on Gasthuisplein where the grenade was found, has not been ruled out as a possible target.

The mayor has organised large-scale searches of campsites and industrial premises in the municipality, which borders the province of Noord-Brabant. The raids exposed illegal businesses and led to tens of thousands of euros being confiscated.

A police spokesman said: ‘It is absolutely unclear who the action was directed against or from whom it originated. We cannot make any comment about other lines of inquiry. The rumours that are doing the rounds are being investigated.’