Amsterdam - Italian national Giuseppe Nirta, aged 35, will remain in custody in the Netherlands until an Amsterdam court has decided whether or not he will be extradited to Italy to serve a prison sentence of 14 years and 18 months for dealing in drugs.

The leader of the so-called 'Ndrangheta clan from Italy is also a suspect for the German police in the gangland-style massacre.

In August 2007, a total of six Italians were murdered in Duisburg.

Wim de Bruin, spokesman of the Dutch public prosecutor, told Deutsche Presse-Agentur dpa on Tuesday that Italy had filed its request for the Nirta's arrest last month.

"Italy also provided the Dutch authorities with information about Nirta's possible whereabouts," De Bruin said. "The Amsterdam police subsequently tracked him down quickly."

According to Italian media reports, Nirta was arrested after the Italian police had monitored three sisters of Nirta's brother-in-law Giovanni Strangio.

The latter, aged 29, is also a suspect in the Duisburg massacre and the only one for whom an international warrant for his arrest has been filed.

De Bruin, a spokesman for the public prosecutor, on Tuesday said the Italian authorities have a maximum of 20 days to file their request for Nirta's extradition.

After its receipt it will take up to three months until the Amsterdam court will rule in a public hearing whether or not Nirta will be extradited to Italy.

Toine Spapens, an expert in international police cooperation, meanwhile told Deutsche Presse-Agentur dpa on Tuesday that it depends on national Italian law whether or Nirta will ever be tried for his possible involvement in the Duisburg massacre if he will indeed be extradited to Italy.

"Many countries do not extradite their citizens to foreign countries to be tried in local criminal cases," Spapens said. (dpa)