Some 1,500 police officers, soldiers, tax officials and others were involved in a string of raids at 100 locations across the southern Dutch provinces on Monday morning in a major crackdown on drugs-related crime.

The operation, nicknamed Operation Trefpunt, is one of the biggest ever combined police campaigns, the Telegraaf says. The investigation into the gang, involved in the production of drugs like amphetamines and ecstasy, has been ongoing for three years.

The focus of attention is on an industrial estate in Best, where the public prosecution states a party supplies rental company has been used as a cover for the production and trade of synthetic drugs. Some 700 people are said to have visited the party company in the years it has been under police observation.

There were also been dawn raids on Brabant property in Eindhoven, Tilburg, Waalre and Katsheuvel. Elseswhere premises in Limburg, Rotterdam and Belgium have also been searched, the public prosecution department said.

Police said on Monday afternoon that 51 people had been arrested. There are three main suspects, one of whom was picked up in the Czech Republic, according to broadcaster Nos.

The main investigation has also led to a number of spin-off investigations concentrating on weapons dealing and drugs laboratories.

Update April 5

In total 55 people were arrested and 124 premises raided by police as part of the Operation Trefpunt campaign. Some 55 kilos of drugs were found, including 15 kilos of MDMA, 15 kilos of ‘pills’ and 20 kilos of amphetamines.

Six drugs labs dismantled including one on the Spaanse Polder in Rotterdam which contained 4,000 litres of chemicals used to make amphetamines. Police also seized almost €500,000 in cash and 20 weapons, including pistols, an Uzi and a Kalashnikov.

Other items taken in by police included two Harley Davidson motorbikes, 26 cars, a lorry, two boats, a jet ski and a quad bike.