The public prosecution department has failed to collect dna specimens from almost 12,000 convicted criminals whose dna should be included in the national data bank.

The total includes dozens of murderers, rapists and people convicted of sexual assault who have escaped the compulsory test, RTL news reports.

Since 2005, everyone convicted of a crime punishable by four years or more in jail in the Netherlands must give a dna sample. This is kept on the data base for 20 years.

RTL news, which bases its claim on justice ministry figures, says while 3,800 of the people not included in the dna data bank were convicted of simple theft, 1,400 were found guilty of assault.

In addition, 18 rapists, 52 people jailed for human trafficking, 10 murderers and 68 people convicted of manslaughter have escaped the test.

Lawyer Richard Korver told the broadcaster it is extremely worrying that so many people convicted of violent crimes have not been tested. ‘It is well known that they often re-offend,’ he said.

One of the reasons so many people are not included in the data bank is that they failed to show up for an appointment to have their dna taken, RTL news says.

The public prosecution department said in a reaction that it is working with police and justice ministry officials to track down as many people as possible.

The police say the law should be changed to allow samples for the data bank to be taken before someone is found guilty in court.