The debate was sparked by a number of well-publicised arrests of child drug dealers in Berlin – children barely in their teenage years who are being used and abused by drug-dealing gangs.

One 11-year-old was found three times within a week, selling heroin at a Berlin underground train station.

A 13-year-old who was caught doing the same thing and taken to an emergency children’s home Kindernotdienst left shortly afterwards and is at large somewhere in the city.

Such youngsters are attractive to the gangs precisely because being under 14 means they cannot be arrested, nor charged with crimes – and their young age makes them vulnerable to bullying and manipulation.

Although they are housed in homes designed for orphans, or institutions set up by child emergency services, they cannot be held there and often just walk out – back into the influence of the gangs.

“Such children must be accommodated in closed, secure institutions in order to remove them from the criminal circles to which they keep returning from the open institutions,” said Bavaria’s interior minister Joachim Herrmann of the Christian Social Union.

He said the aim was to protect the children from criminal gangs who use them as drug dealers and thieves because they are not yet legally deemed criminally responsible.

His plea was echoed by his counterpart in Lower Saxony, Uwe Schünemann, from the Christian Democratic Union. “If it enables us to prevent young people becoming criminals, or becoming anchored in these criminal careers, then it is an important step towards a safer society,” he said.

A spokesman for Berlin’s interior minister Ehrhard Körting, from the Social Democratic Party, also agreed. “Homes where the children can come and go as they please are completely pointless,” he said.

“Yacht cruises and youth community houses are no use,” said Reinhard Grindel, CDU parliamentary party interior policy expert. He said secure institutions would be better where the young perpetrators could be counselled around the clock by experienced social workers.

Such institutions are the only answer, agreed Konrad Freiberg, head of the police trade union.

Yet according to the Welt am Sonntag newspaper, there are only five such homes in the whole country, and places at them are therefore rare and difficult to get.

Meanwhile the head of the criminological institute in Lower Saxony Christian Pfeiffer criticised the calls from politicians as populist knee-jerk reactions, saying that the idea of secure institutions are not supported by social scientists.