Amsterdam - More than half of young Dutch nationals of Moroccan origin in Rotterdam have a criminal record, according to a study published in the Dutch daily Volkskrant on Thursday.

The study, performed by researchers of Rotterdam's Erasmus University and the Royal University of Utrecht, said 55 per cent of Dutch-Moroccans aged 18 to 24 in Rotterdam have a criminal record.

Among young men from the Dutch Antilles and Surinam living in Rotterdam, 40 per cent have a criminal record, compared with 36 per cent of Dutch-Turks in the city.

Among native Dutch nationals from Rotterdam, 18.4 per cent have a police record.

The study found that once they have a police record, 90 per cent of Dutch-Moroccans return to criminal activity, compared with 60 per cent of ethnic Dutch nationals.

The study's crime statistics among ethnic groups in the Netherlands are far higher than those estimated so far by the Dutch Central Bureau of Statistics (CBS).

This can partly be explained by the fact that Rotterdam is the only Dutch city which has registered the ethnicity of criminals since 2002.

In addition, the study's methodology differed from other studies.

Contrary to the CBS, the study also included children of migrants, the so-called 'second generation' born in the Netherlands, among each ethnicity.

With a population of almost 600,000, Rotterdam is second largest city of the Netherlands. Half of its inhabitants are not native or have at least one foreign-born parent. Some 40,000 inhabitants are ethnic Moroccans.(dpa)