The duo, suspected of being members of a Swiss-based cell of the powerful Italian crime organization ‘Ndrangheta, have refused to be extradited.

Since they are naturalized Swiss, they cannot be extradited against their will, the Swiss federal justice office said in a statement on Thursday.

According to the ministry, the additional 15 alleged ‘Ndrangheta members arrested in Switzerland on March 8th – who are all Italian – are also refusing to be extradited to Italy, as requested by Rome.

Twelve of them were detained in the northern canton of Thurgau, one in the neighbouring canton of Zurich and two in the Valais.

Italian police believe the ‘Ndrangheta group – which they describe as the most active, richest and most powerful crime syndicate in Europe – uses legitimate activities in northern Italy to recycle the huge amounts of cash generated by their drugs business.

In the statement, the Swiss said they must now examine if Italy’s request meets the conditions demanded by the European convention on extradition.

Switzerland is obliged to extradite the two suspects arrested in the canton of Valais since they were already sentenced to nine and six years jail respectively by a court in Reggio Calabria, Southern Italy, in 2014 for offences committed in Italy.

Twelve of the group have been released on bail, since the justice ministry “judges that the flight risk is slim”.

In their case, there is no obligation for the Swiss to comply with Italy’s extradition request since their alleged offences were committed in Switzerland.