The Netherlands tapped the phones of Mexican drugs baron ‘El Chapo’ for several months on behalf of the US, because Dutch privacy laws were not as strict as those in America or Canada, the Volkskrant reported on Wednesday.

El Chapo, real name Joaquin Guzman, is currently on trial in the US. The Dutch listening-in programme took place from April 2011 to January 2012, an FBI agent told his trial on Tuesday. The Volkskrant says the operation lasted for 18 months.

The wire-tapping operation was enabled by an FBI informant who had set up a Blackberry network for El Chapo’s organisation. The FBI server used to store all communications traffic made via the network was first placed in Canada but had to be moved because of tough privacy laws, the Volkskrant said.

The US was not an option because the ‘operation might be noticed’ and the US has relatively tough rules on tapping servers, sources told the paper.

‘Because the US and the Netherlands work closely together and the Netherlands is relaxed about requests for tapping, the FBI placed the server in a data centre operated by Leaseweb, just outside Haarlem,’ the Volkskrant said.

The Netherlands did not know the full extent of the importance of the operation nor that El Chapo was the main target until 2013.

Sing song

The FBI agent told Guzman’s trial on Tuesday that the 61-year-old was easily identifiable by his voice which had a ‘kind of a sing-songy nature to it’ and a ‘nasally undertone.’

The agent told the trial, which started in November, that the FBI tapped into more than 800 calls on the Blackberry encrypted system.

Guzman is on trial for his role as leader of the Sinaloa drugs cartel and was extradited to the US two years ago.

Close relationship

The Volkskrant’s sources say the Netherlands and the US continue to work closely together in crime investigations.

Some 125 requests for help from US officials are currently open, the sources said. These requests range from tapping computer servers to providing people’s Whatsapp history. All requests have to be checked to make sure they are legal with the public prosecution department, the paper said.